Author: Buffat, X.
Paper Title Page
WEPC120 Status of JMAD, the JAVA-API for MADX 2292
 
  • K. Fuchsberger, X. Buffat, Y.I. Levinsen, G.J. Müller
    CERN, Geneva, Switzerland
 
  MADX (Methodical Accelerator Design) is the de-facto standard software for modeling accelerator lattices at CERN. This feature-rich software package is implemented and still maintained in the programming languages C and FORTRAN. Nevertheless the controls environment of modern accelerators at CERN, e.g., of the LHC, is dominated by JAVA applications. A lot of these applications, for example, for lattice measurement and fitting, require a close interaction with the numerical models, which are all defined by the use of the proprietary MADX scripting language. To close this gap an API to MADX for the JAVA programming language (JMAD) was developed. JMAD was first presented to the public about one year ago. In the meantime, a number of improvements were done, and additional MADX features (e.g., tracking) were made available for JAVA applications. Additionally, the graphical user interface was improved, and the first release as open source software is in reach. This paper describes the current status and some new features of the project, as well as some usage examples.  
 
TUPZ028 Beam Based Optimization of the Squeeze at the LHC 1867
 
  • X. Buffat
    EPFL, Lausanne, Switzerland
  • M. Lamont, S. Redaelli, J. Wenninger
    CERN, Geneva, Switzerland
 
  The betatron squeeze is a critical operational phase for the LHC because it is carried out at top energy, with the maximum stored energy and with reduced aperture margins in the superconducting triplets. A stable operation with minimum beam losses must be achieved in order to ensure a safe and efficient operation. The operational experience at the LHC showed that this is possible. The operation in 2010 is reviewed. In particular, orbit, tune and chromaticity measurements are investigated and correlated to beam losses. Different optimizations are then proposed towards a more efficient and robust operation. The improvements obtained for the operation in 2011 are presented.  
 
TUPZ029 Observation of Coherent Beam-beam Effects in the LHC 1870
 
  • X. Buffat
    EPFL, Lausanne, Switzerland
  • R. Calaga, S.M. White
    BNL, Upton, Long Island, New York, USA
  • R. Giachino, W. Herr, G. Papotti, T. Pieloni
    CERN, Geneva, Switzerland
 
  Early collisions in the LHC with a very limited number of bunches with high intensities indicated the presence of coherent beam-beam driven oscillations. Here we discuss the experimental results and compare with the expectations.  
 
TUPZ030 Simulation of Linear Beam Parameters to Minimize the Duration of the Squeeze at the LHC 1873
 
  • X. Buffat
    EPFL, Lausanne, Switzerland
  • G.J. Müller, S. Redaelli, M. Strzelczyk
    CERN, Geneva, Switzerland
 
  The betatron squeeze allows to increase the luminosity of a collider by reducing the β function at the interaction points. This operation has shown to be very critical in previous colliders. In this state of mind, the squeezing was performed extremely safely during the first year of operation of the Large Hadron Collider, at the expense of the duration of the process. As the turnaround time is a relevant parameter for the integrated luminosity, a squeeze of shorter duration is proposed for 2011 and further. MadX simulation of linear beam parameters based on settings extracted from the LHC control system are used to justify the proposal. Further optimization of the squeeze setting generation is also discussed.