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Portmann, G.J.

Paper Title Page
MPPE074 Commissioning of a Locally Isochronous Lattice at ALS 3922
 
  • W. Wan, W.E. Byrne, H. Nishimura, G.J. Portmann, D. Robin, F. Sannibale, A. Zholents
    LBNL, Berkeley, California
 
  Funding: Work supported by the Director, Office of Energy Research, Office of Basic Energy Science, Material Sciences Division, U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

With the advance of ultrafast science, manipulating electron beam at the sub-micron and nanometer scale has been actively pursued. A special lattice of the ALS storage ring was conceived to studythe sub-micron longitudinal structure of the beam. It contains sections that are isochronous to the firstorder. Due to the practical constraints of the accelerator, sextupoles have to be off and the dispersion at the injection point is 60 cm, which make commissioning a highly nontrivial task. After a few months of tuning, we have been able to store at 30 mA of beam at the life time of 2 hours. After a brief introduction to the motivation of the experiment and the design of the lattice, the process and more detailed results of the commissioning will be presented. Future plan will also be discussed.

 
TOPC003 Beam Measurements and Upgrade at BL 7.2, the Second Diagnostics Beamline of the Advanced Light Source 281
 
  • T. Scarvie, A. Biocca, N. Kelez, M.C. Martin, T. Nishimura, G.J. Portmann, F. Sannibale, E. Williams
    LBNL, Berkeley, California
 
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

Beamline BL 7.2 of the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory is a beam diagnostics system that uses the synchrotron radiation (SR) emitted by a dipole magnet. It consists of two branches, in the first one the x-ray portion of the SR is used in a pinhole camera system for measuring the transverse profile of the beam. The second branch is equipped with a x-ray BPM system and with a multipurpose port where the visible and the infrared part of the SR can be used for various applications such as bunch length measurements and IR coherent synchrotron radiation experiments. The pinhole system has been commissioned at the end of 2003 and since then is in successful operation. The installation of the second branch has been completed recently and the results of its commissioning are presented in this paper together with examples of beam measurements performed at BL 7.2.

 
FPAT077 An Accelerator Control Middle Layer Using Matlab 4009
 
  • G.J. Portmann
    LBNL, Berkeley, California
  • W.J. Corbett, A. Terebilo
    SLAC, Menlo Park, California
 
  Funding: U.S. Department of Energy under Contract No. DEAC03-76SF00098.

Matlab is a matrix manipulation language originally developed to be a convenient language for using the LINPACK and EISPACK libraries. What makes Matlab so appealing for accelerator physics is the combination of a matrix oriented programming language, an active workspace for system variables, powerful graphics capability, built-in math libraries, and platform independence. A number of software toolboxes for accelerators have been written in Matlab – the Accelerator Toolbox (AT) for machine simulations, LOCO for accelerator calibration, Matlab Channel Access Toolbox (MCA) for EPICS connections, and the Middle Layer. This paper will describe the MiddleLayer software toolbox that resides between the high-level control applications and the low-level accelerator control system. This software was a collaborative effort between ALS and Spear but was written to easily port. Five accelerators presently use this software – Spear, ALS, CLS, and the X-ray and VUV rings at Brookhaven. The Middle Layer functionality includes energy ramp, configuration control, global orbit correction, local beam steering, insertion device compensation, beam-based alignment, tune correction, response matrices, and script-based physics studies.