Controls and Computing

Paper Title Page
ROPA001 XAL Application Programming Structure 79
  • J. Galambos, C. Chu, S.M. Cousineau, V.V. Danilov, J.G. Patton, T.A. Pelaia, A.P. Shishlo
    ORNL, Oak Ridge, Tennessee
  • C.K. Allen
    LANL, Los Alamos, New Mexico
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

XAL is an application programming framework used at the Spallation Neutron Source (SNS) project in Oak Ridge. It is written in Java, and provides users with a hierarchal view of the accelerator. Features include database configuration of the accelerator structure, an online envelope model that is configurable from design or live machine values, an application framework for quick-start GUI development, a scripting interface for algorithm development, and a common toolkit for shared resources. To date, about 25 applications have been written, many of which are used extensively in the SNS beam commissioning activities. The XAL framework and example applications will be discussed.

ROPA002 CLS: A Fully Open-Source Control System 136
  • E. Matias, R. Berg, T. Johnson, R. Tanner, T. Wilson, G. Wright, H.Z. Zhang
    CLS, Saskatoon, Saskatchewan
  The Canadian Light Source is one of the first major accelerator facility to adopt a fully open source control system. The control system is based on Experimental Physics and Industrial Control System (EPICS) in use at may other facilities. From the outset CLS utilised RTEMS and Linux as the underlying operating systems for real-time control computers, operator interface computers and servers. When communicating with PLC and other intelligent devices CLS has also adopted a policy of using open communications protocols where possible. Combined these strategies have lead to a system that can easily evolve over the life of the facility without being tied to specific hardware or software suppliers. The operational experience over the past few years has indicates the selected architecture is sufficiently robust and reliable.  
ROPA003 Present Status of the J-PARC Control System 302
  • T. Katoh, K.  Furukawa, N. Kamikubota, H. Nakagawa, J.-I. Odagiri, G.S. Shen, Y. Takeuchi, N. Yamamoto, M. Yoshii
    KEK, Ibaraki
  • H. Sakaki, H. Sako, H. Takahashi, F. Tamura, H. Yoshikawa
    JAERI, Ibaraki-ken
  Construction of the J-PARC control system is in progress and the present status is reported. The control system is based on EPICS tool-kit used in KEKB and other accelerator control systems at KEK. The control hardware and network system for Linac and RCS(Rapid Cycling Synchrotron) have been installed and software is under development now. The operation of Linac is expected in next year. The test of the first part of the accelerator complex; e.g. ion source, RFQ and the first DTL(20 MeV) were done at KEK site. Development of various software such as device drivers for the new equipment, device support routines, and some application programs for operators were also developed.  
ROPA004 CEBAF Control Room Renovation 378
  • M. Spata, A. Cuffe, H. Fanning, T.C.O. Oren
    Jefferson Lab, Newport News, Virginia
  The Machine Control Center at Jefferson Lab's Continuous Electron Beam Accelerator Facility was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week period with no interruption to beam operations. We present the results of this effort.  
ROPA005 High Level Control Applications for SOLEIL Commissioning and Operation 481
  • L.S.N. Nadolski, J. Chinkumo, K. Ho, N.L. Leclercq, M.O. Ounsy, S. Petit
    SOLEIL, Gif-sur-Yvette
  Funding: Synchrotron SOLEIL

The SOLEIL control system, namely TANGO developed in collaboration with ESRF, is now mature and stable. TANGO has also been chosen now by several other laboratories. High-level control applications implemented in the control room for the storage ring, the two transfer lines, and the booster will be described in this paper. Three kinds of tools for commissioning are used. First the generic TANGO tools (alarms, simple graphical control applications), which allow us to control in a simple way any TANGO Device Server. Secondly a Matlab Middle Layer (adapted from ALS and SPEAR3): Matlab is fully interconnected with TANGO; it is used primarily for writing Physics control applications. Finally Globalscreen, a commercial SCADA software devoted for building operation applications has been selected (panels for controlling or displaying setpoint, readback values, status of equipments). In addition an overview of the historical and short-term databases for the accelerators will be given. They have been developed in house and tested during the first commissioning.

ROPA006 Terascale Beam-Beam Simulations for Tevatron, RHIC and LHC 535
  • J. Qiang
    LBNL, Berkeley, California
  Funding: This work was supported by a SciDAC project in accelerator physics which is supported by the US DOE/SC Office of High Energy Physics and the Office of Advanced Scientific Computing Research.

In this paper, we report on recent advances in terascale simulations of the beam-beam effects in Tevatron, RHIC and LHC. Computational methods for self-consistent calculation of the beam-beam forces are reviewed. Applications to the studies of the multiple bunch beam-beam interactions in the Tevatron and the RHIC will be presented. The study of emittance growth due to the beam-beam interactions in the LHC will also be presented.

ROPA007 Vlasov Simulations of Beams and Halo 581
  • E. Sonnendrucker, M. Gutnic, M. Haefele, G. Latu
    IRMA, Strasbourg
  • J.-L. Lemaire
    CEA/DIF/DPTA/SP2A, Bruyeres-le-Chatel
  Even though PIC simulations have proven an efficient tool for beam simulations for many years, they are subject to numerical noise which only decreases slowly when the number of particles is increased. Therefore other methods might be preferable, when one is interested in accurate simulations of high intensity beams especially in the low density part of phase space. We have been developing new methods based on the direct resolution of the Vlasov equation on a grid of phase space. In order for these methods to be efficient special care needs to be taken to optimize the number of necessary grid points. We shall describe two different approaches that are used to this aim: moving grid methods and wavelet based automatic grid refinement. Beam simulations in different configurations using direct Vlasov methods will be presented.  
ROPA008 The Grid
  • W.-D. Klotz
    ESRF, Grenoble
  • R. Pordes
    Fermilab, Batavia, Illinois
  Grid technology is widely emerging. Grid computing, most simply stated, is distributed computing taken to the next evolutionary level. The goal is to create the illusion of a simple, robust yet large and powerful self managing virtual computer out of a large collection of connected heterogeneous systems sharing various combinations of resources. This talk will give a short history how, out of lessons learned from the Internet, the vision of Grids was born. Then the extensible anatomy of a Grid architecture will be discussed. The talk will end by presenting a selection of major Grid projects in Europe and US and if time permits a short on-line demonstration.  
ROPA009 Bridging Timescales for Simulating Electron Clouds
  • R.H. Cohen, A. Friedman
    LLNL, Livermore, California
  • J.-L. Vay
    LBNL, Berkeley, California
  Funding: Work performed under the auspices of the U.S. Department of Energy by U. C. LLNL under contract No. W-7405-Eng-48 and by U.C. LBNL under Contract DE-AC03-76F00098.

For a range of acclerator applications, accurate simulation of electron-cloud effects requires self-consistent simulation of electrons and the main positively-charged accelerated species. For systems with multipole focusing magnets, the simulation must span timescales from electron cyclotron periods to the beam duration. We have devised a scheme to bridge over the shortest (electron cyclotron) timescale based on interpolation between full dynamics and drift kinetics.* We describe the method and results for heavy-ion beam simulations. We also discuss options for bridging to ion-transit timescales.

*R. H. Cohen, A. Friedman, S. M. Lund, A. W. Molvik, E. P. Lee, T. Azevedo, L.-L. Vay, P. Stoltz and S. Veitzer, PRST-AB 7, 124201 (2004)

ROPA010 Component/Connection/Signal Modeling of Accelerator Systems 707
  • D. Dohan
    ANL, Argonne, Illinois
  Funding: Work supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

This paper presents a pragmatic global approach to data modeling a complex facility such as a particle accelerator. By successively partitioning the facility into collaborating subsystems, one eventually arrives at the component level–the point at which the subsystem is replaceable as a single unit. The fundamental goal of the model is to capture the dynamical relationships (i.e., the connections) that exist among the accelerator components. Components participate in one or more of three connection types: control, housing, and power. These connections are captured in a multi-hierarchical model capable of handling any component of the accelerator, from the macro scale (magnets, power supplies, racks, etc.) to the embedded scale (circuit board components), if desired. The connection approach has been used to model the signal flows between the component via their port connections. The result is a schema for a cable database that provides end-to-end signal tracing throughout the facility. The paper will discuss the multi-hierarchy nature of the model and its success in replacing the "Revision Controlled Drawing" approach to system documentation.

FPAT044 Low Cost Magnetic Field Controller 2833
  • A.A. Malafronte, M.N. Martins
    USP/LAL, Bairro Butantan
  Funding: Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq.

The Physics Institute of the University of São Paulo (IFUSP) is building a continuous wave (cw) racetrack microtron. This machine has several dipole magnets, like the first and second stage recirculators, and a number of smaller ones in the transport line. These magnets must produce very stable magnetic fields to allow the beam to recirculate along very precise orbits and paths. Furthermore, the fields must be reproducible with great accuracy to allow an easier setup of the machine, though the effects of hysteresis tend to jeopardize the reproducibility. If the magnetic field is chosen by setting the current in the coils, temperature effects over the magnet and power supply tend to change the field. This work describes an inexpensive magnetic field controller that allows a direct measure of the magnetic field through an Hall probe. It includes a microcontroller running a feedback algorithm to control the power supply, in order to keep the field stable and reproducible. The controller can also execute algorithms to ramp up and down the power supply in a specific mode, in order to reduce hysteresis.