• R.D. Lifshitz
  Technion, Haifa
• D. Schulte
  CERN, Geneva

A system for automatic beam steering has been implemented at the CTF3 linear accelerator. Beam position readings are logged while corrector magnet strengths are scanned over a given range, thus giving a steering response measurement. Assuming linearity, a response matrix is constructed and used to automatically optimize the beam trajectory along the linac. Using a simple BPM-reading minimization for trajectory correction, this system has been tested in the 2004 CTF3 summer run. Although not in routine operation, it has already proved useful as a tool for the machine setup and operation. In this paper, the automatic steering system for the CTF3 linac is introduced, trajectory correction results are presented, and the agreement with a computer model of the machine is discussed.

• N. Malitsky, K.A. Brown, N. D'Imperio, A.V. Fedotov, J. Kewisch, A.U. Luccio, F.C. Pilat, V. Ptitsyn, T. Satogata, S. Tepikian, J. Wei
  BNL, Upton, Long Island, New York
• R.M. Talman
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York

The paper presents an interface encompassing the RHIC online ramp model and the UAL offline simulation framework. The resulting consolidated facility aims to minimize the gap between design and operational data, and to facilitate analysis of RHIC performance and future upgrades in an operational context. The interface is based on the Accelerator Description Exchange Format (ADXF), and represents a snapshot of the RHIC online model which is in turn driven by machine setpoints. This approach is also considered as an intermediate step towards integrating the AGS and RHIC modeling environments to produce a unified online and offline AGS model for operations.

• P. Lebrun, T. Sen, J. You, Z.Y. Yuan
  Fermilab, Batavia, Illinois
• E. Todesco
  CERN, Geneva

• L. Michelotti, J.-F. Ostiguy
  Fermilab, Batavia, Illinois

We introduce CHEF, a program built on a "Collaborative Hierarchical Exploratory Framework" for doing optical calculations in accelerator physics. CHEF organizes and shares information between independent components that employ graphical user interfaces for interactive use. Among them are: a browser to display the beamline model's structure; a site viewer to show a line's geometry; phase space windows to oversee development of tracking calculations; a trace window to display the passage of a probe particle through beam position monitors; a plotter for displaying optical functions; a parser which constructs beamline models defined in MAD8 format and allows for interactive editing and debugging of the lattice files. Calculations are carried out by a hierarchy of C++ class libraries, most notably: MXYZPTLK handles automatic differentiation and differential algebra; BEAMLINE contains classes for modeling accelerator components; PHYSICS_TOOLKIT encapsulates specific calculations. Python bindings to these libraries and to CHEF's components, in conjunction with an embedded interpreter, provide a mechanism to extend and customize CHEF's functionality.

• J.-F. Ostiguy, M. Kriss, M. McCusker-Whiting, L. Michelotti
  Fermilab, Batavia, Illinois

Fermilab is a large accelerator complex with six rings and sixteen transfer beamlines operating in various modes and configurations, subject to modifications, improvements and occasional major redesign. Over the years, it became increasingly obvious that a centralized lattice repository with the ability to track revisions would be of great value. To that end, we evaluated potentially suitable revision systems, either freely available or commercial, and decided that expecting infrequent users to become fully conversant with complex revision system software was neither realistic nor practical. In this paper, we discuss technical aspects of the recently introduced FNAL Accelerator Division's Lattice Repository, whose fully web-based interface hides the complexity of Subversion, a comprehensive open source revision system. In particular we emphasize how the architecture of Subversion was a key ingredient in the technical success of the repository's implementation.

• V. Papadimitriou, T.B. Bolshakov, P. Lebrun, S. Panacek, A.J. Slaughter, A. Xiao
  Fermilab, Batavia, Illinois

Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Acquisition and Analysis (SDA) has been developed to fulfill this need. Data is stored in a relational database, and is served to programs and users via Web-based tools. Summary tables are systematically generated during and after a store. These tables, the Supertable, and the Recomputed Emittances and Recomputed Intensity tables are discussed here. This information is also accesible in JAS3 (Java Analysis Studio version 3).

• C.K. Allen
  LANL, Los Alamos, New Mexico
• E. Schuster
  Lehigh University, Bethlehem, Pennsylvania

We present an optimal control strategy for beam steering where the operator can specify a variety of optimality conditions by selecting a parameter set describing an optimally steered beam. Novel approaches here include the ability to base optimality on the beam state throughout the entire beamline, rather than just at BPM locations. Moreover, we also may use the trajectory slope to base our optimality criteria. To achieve this feature we must introduce model dependency. Specifically, we predict the state of the beam from BPM measurements, the set-point of the steering magnets, and a model of beam behavior. The predictions are then used to calculate the optimum setting for steering magnets. The optimal control problem has rich mathematical structure that can be exploited and we cover some topics as they apply to accelerator systems.

ckallen@lanl.gov

• J. Beebe-Wang
  BNL, Upton, Long Island, New York

Coupling correction is essential for the operational performance of RHIC. The independence of the transverse degrees of freedom makes diagnostics and tune control easier, and it is advantageous to operate an accelerator close to the coupling resonance to minimize nearby nonlinear sidebands. An automated decoupling application has been developed at RHIC for coupling correction during routine operations. The application decouples RHIC globally by minimizing the tune separation through finding the optimal settings of two orthogonal skew quadrupole families. The program provides options of automatic, semi-automatic and manual decoupling operations. It accesses tune information from all RHIC tune measurement systems: the PLL (Phase Lock Loop), the high frequency Schottky system, and the tune meter. It also supplies tune and skew quadrupole scans, finding the minimum tune separation, display the real time results and interface with the RHIC control system. We summarize the capabilities of the decoupling application, and discuss the operational protections incorporated in the program. We also report the decoupling performances with the application during the RHIC 2005 run.

• A. Xiao, T.B. Bolshakov, P. Lebrun, E.S. McCrory, V. Papadimitriou, A.J. Slaughter
  Fermilab, Batavia, Illinois

• W. Blokland, D.J. Murphy, J.D. Purcell
  ORNL, Oak Ridge, Tennessee
• A.V. Liyu
  RAS/INR, Moscow
• C.D. Long
  Innovative Design, Knoxville, Tennessee
• M. Sundaram
  University of Tennessee, Knoxville, Tennessee

The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based running Embedded Windows XP and LabVIEW. The diagnostics instruments communicate with the control system using the Channel Access (CA) protocol of the Experimental Physics and Industrial Control System (EPICS). This paper describes the Diagnostics Group’s approach to collecting data from the instruments, processing it, and presenting live in a summarized way over the web. Effectively, adding a supervisory level to the diagnostics instruments. One application of this data mining is the "Diagnostics Status Page" that summarizes the insert-able devices, transport efficiencies, and the mode of the accelerator in a compact webpage. The displays on the webpage change automatically to show the latest and/or most interesting instruments in use.

• C. Chu, T.A. Pelaia
  ORNL, Oak Ridge, Tennessee

Automated beam trajectory correction with dipole correctors is developed and tested during the Spallation Neutron Source warm linac commissioning periods. The application is based on the XAL Java framework with newly developed optimization tools. Also, dipole corrector polarities and strengths, and beam position monitor (BPM) polarities were checked by an orbit difference program. The on-line model is used in both the trajectory correction and the orbit difference applications. Experimental data for both applications will be presented.

• J. Galambos, A.V. Aleksandrov, C. Deibele, S. Henderson
  ORNL, Oak Ridge, Tennessee

To assist the beam commissioning in the Spallation Neutron Source (SNS) linac, a general purpose RF tuning application has been written to help set RF phase and amplitude. It follows the signature matching procedure described in Ref.* The method involves varying an upstream Rf cavity amplitude and phase settings and comparing the measured downstream beam phase responses to model predictions. The model input for cavity phase and amplitude calibration and for the beam energy are varied to best match observations. This scheme has advantages over other RF tuning techniques of not requiring intercepting devices (e.g. Faraday Cups), and not being restricted to a small linear response regime near the design values. The application developed here is general and can be applied to different RF structure types in the SNS linac. Example applications in the SNS Drift Tube Linac (DTL) and Coupled Cavity Linac (CCL) structures will be shown.

*T.L. Owens, M.B. Popovic, E.S. McCrory, C.W. Schmidt, L. J. Allen, "Phase Scan Signature Matching for Linac Tuning," Particle Accelerators, 1994 Vol 98, p. 169.

• M. Sundaram
  University of Tennessee, Knoxville, Tennessee
• W. Blokland
  ORNL, Oak Ridge, Tennessee
• C.D. Long
  Innovative Design, Knoxville, Tennessee

The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1.0 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based and will run Windows for its OS and LabVIEW as its programming language. The diagnostics platform as well as other control systems and operator consoles use the Channel Access (CA) protocol of the Experimental Physics and Industrial Control System (EPICS) to communicate. This paper describes the tools created to evaluate the diagnostic instrument using our standard programming environment, LabVIEW. The tools are based on the LabVIEW Channel Access library and can run on Windows, Linux, and Mac OS X. The data-acquisition tool uses drop and drag to select process variables organized by instrument, accelerator component, or beam parameters. The data can be viewed on-line and logged to disk for later use. A drag and drop display creation tool supports the quick creation of graphical displays to visualize the data produced by the instruments without the need for programming.

• S.J. Cooke, B. Levush
  NRL, Washington, DC

We present results of a new method for fast, accurate calculation, in 3-D, of the electromagnetic mode spectrum of long, tapered accelerator structures. Instead of discretizing the entire structure directly and solving a huge matrix eigenvalue problem, we use a new two-step technique that scales much better to long, multi-cavity structures. In the first step we compute a small number of eigenmodes of individual cavities, achieving 0.05% frequency accuracy using a new second-order finite-element code. In the second step we use these 3-D mode solutions as field basis functions to obtain a reduced matrix representation of Maxwell’s equations for the complete structure. Solving the reduced system takes just a few minutes on a desktop PC even with more than 100 non-identical cavities, and gives the complete mode spectrum in the first few bands of the structure. By judicious choice of the basis modes, we retain 0.05% frequency accuracy for these global solutions, and can reconstruct the complete 3-D field of each mode in order to perform beam-interaction calculations. Solution times are faster by orders of magnitude than comparable calculations using a direct finite-element method.

• A.V. Novikov-Borodin, V.A. Kutuzov
  RAS/INR, Moscow
• P.N. Ostroumov
  ANL, Argonne, Illinois

There are several heavy-ion linac projects being developed worldwide. For example, the Rare Isotope Accelerator Facility [J.A. Nolen, Nucl. Phys. A. 734 (2004) 661] currently being designed in the U.S. will use both heavy-ion and light ion beams to produce radionuclides via the fragmentation and spallation reactions, respectively. With simultaneous beam delivery to more than one target independent adjustment of relative beam intensities is essential. A fast traveling wave chopper can be used to modulate cw beam intensity at low energy ~200 keV/u. Such a device should have high frequency characteristics at high power level. By increasing the wave impedance of the traveling wave structure up to 200 Ohm one can reduce power requirements to the fast voltage pulser. Several design options of the high-impedance structure are discussed.

• E.H.R. Gaxiola, J. Bertin, F. Caspers, L. Ducimetière, T. Kroyer
  CERN, Geneva

• E.H.R. Gaxiola, G. Arduini, W. Höfle, F. Roncarolo, E. Vogel, E. Vossenberg
  CERN, Geneva

• L. Yin, K. J. Bowers, R.C. Carlson, BG.D. DeVolder, J. T. Kwan, JR.S. Smith, CM.S. Snell
  LANL, Los Alamos, New Mexico
• MJ.B. Berninger
  Bechtel Nevada, Los Alamos, New Mexico

• C.M. Celata, F.M. Bieniosek, P.A. Seidl
  LBNL, Berkeley, California
• A. Friedman, D.P. Grote
  LLNL, Livermore, California
• L.R. Prost
  Fermilab, Batavia, Illinois

In heavy-ion-driven inertial fusion accelerator concepts, dynamic aperture is important to the cost of the accelerator, most especially for designs which envision multibeam linacs, where extra clearance for each beam greatly enlarges the transverse scale of the machine. In many designs the low-energy end of such an accelerator uses electrostatic quadrupole focusing. The dynamic aperture of such a lattice has been investigated for intense, space-charge-dominated ion beams using the 2-D transverse slice version of the 3-D particle-in-cell simulation code WARP. The representation of the focusing field used is a 3-D solution of the Laplace equation for the biased focusing elements, as opposed to previous calculations which used a less-accurate multipole approximation. 80% radial filling of the aperture is found to be possible. Results from the simulations, as well as corroborating data from the High Current Experiment at LBNL, will be presented.

• E. Henestroza, C. Peters, S. Yu
  LBNL, Berkeley, California
• R.J. Briggs
  SAIC, Alamo, California
• D.P. Grote
  LLNL, Livermore, California

HEDP applications require high line charge density ion beams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strength (B) and line charge density is such that (Ba)² is proportional to the line charge density. Thus it is possible to accelerate a matched beam at constant line charge density. An experiment, NDCX-1c is being designed to test the feasibility of this type of injectors, where we will extract a 1 microsecond, 100 mA, potassium beam at 160 keV, decelerate it to 55 keV (density ~0.2 microC/m), and load it into a 2.5 T solenoid where it will be accelerated to 100–150 keV (head to tail) at constant line charge density. The head-to-tail velocity tilt can be used to increase bunch compression and to control longitudinal beam expansion. We will present the physics design and numerical simulations of the proposed experiment

• W. Waldron, L. R. Reginato
  LBNL, Berkeley, California
• R.J. Briggs
  SAIC, Alamo, California

The basic concept for the acceleration of heavy ions using a helical pulseline requires the launching of a high voltage traveling wave with a waveform determined by the beam transport physics in order to maintain stability and acceleration.* This waveform is applied to the front of the helix, creating over the region of the ion bunch a constant axial acceleration electric field that travels down the line in synchronism with the ions. Several methods of driving the helix have been considered. Presently, the best method of generating the waveform and also maintaining the high voltage integrity appears to be a transformer primary loosely coupled to the front of the helix, generating the desired waveform and achieving a voltage step-up from primary to secondary (the helix). This can reduce the drive voltage that must be brought into the helix enclosure through the feedthroughs by factors of 5 or more. The accelerating gradient is limited by the voltage holding of the vacuum insulator, and the material and helix geometry must be chosen appropriately. The helix must also be terminated into its characteristic impedance, and designs of terminations incorporated into the helix internal enclosure are presented in the paper.

*Briggs, et al, "Helical Pulseline Structures for Ion Acceleration," this conference.

• J.Z. Zhou, C. Chen
  MIT/PSFC, Cambridge, Massachusetts

Image charges have important effects on an intense charged-particle beam propagating through an alternating-gradient (AG) focusing channel with a small circular aperture. This is especially true with regard to chaotic particle motion, halo formation, and beam loss.* In this paper, we examine the dependence of these effects on system parameters such as the filling factor of the AG focusing field, the vacuum phase advance, the beam perveance, and the ratio of the beam size to the aperture. We calculate the percentage of beam loss to the conductor wall as a function of propagating distance and aperture, and compare theoretical results with simulation results from the particle-in-cell (PIC) code PFB2D.

*Zhou, Qian and Chen, Phys. Plasmas 10, 4203 (2003).

• W. Zhang, J. Sandberg, W.-T. Weng
  BNL, Upton, Long Island, New York

This paper present a preliminary design of a 300 kA, 2.5 Hz pulsed power system. This system will drive the focusing horn of proposed Brookhaven AGS Neutrino Super Beam Facility for Very Long Baseline Neutrino Oscillation Experiment. The peak output power of the horn pulsed power system will reach giga-watts, and the upgraded AGS will be capable of delivering 1 MW in beam power.

• S.R. Reeves, C.C. Jensen
  Fermilab, Batavia, Illinois

The temperature stability of the kicker magnet termination resistor assembly directly affects the field flatness and amplitude stability of the kick. Comprehensive thermal enhancements were made to the existing Main Injector resistor assembly design to satisfy NuMI performance specifications. Additionally, a fluid-processing system utilizing Fluorinert® FC-77 high-voltage dielectric was built to precisely control the setpoint temperature of the resistor assembly from 70 to 120F, required to maintain constant resistance during changing operational modes. The Fluorinert® must be continually processed to remove hazardous breakdown products caused by radiation exposure to prevent chemical attack of system components. Design details of the termination resistor assembly and Fluorinert® processing system are described. Early performance results will be presented.

• T.P. Hughes, T.C. Genoni
  ATK-MR, Albuquerque, New Mexico
• H. Davis, M. Kang, B.A. Prichard
  LANL, Los Alamos, New Mexico

The DARHT-2 facility at Los Alamos National Laboratory accelerates a 2 microsecond electron beam using a series of inductive accelerating cells. The cell inductance is provided by large Metglas cores, which are driven by a pulse-forming network. The original cell design was susceptible to electrical breakdown near the outer radius of the cores. We developed a numerical model for the magnetic properties of Metglas over the range of dB/dt (magnetization rate) relevant to DARHT. The model was implemented in a radially-resolved circuit code, and in the LSP* electromagnetic code. LSP simulations showed that the field stress distribution across the outer radius of the cores was highly nonuniform. This was subsequently confirmed in experiments at LBNL. The calculated temporal evolution of the electric field stress inside the cores approximately matches experimental measurements. The cells have been redesigned to greatly reduce the field stresses along the outer radius.

*LSP is a software product of ATK Mission Research (www.lspsuite.net).

• G.J. Caporaso, S.D. Nelson, B.R. Poole
  LLNL, Livermore, California
• R.J. Briggs
  SAIC, Alamo, California

We analyze the sheath helix model of the pulseline accelerator.* We find the dispersion relation for a shielded helix with a dielectric material between the shield and the helix and compare it against the results from 3-D electromagnetic simulations. Expressions for the fields near the beam axis are obtained. A scheme to taper the properties of the helix to maintain synchronism with the accelerated ions is described. An approximate circuit model of the system that includes beam loading is derived.

*"Helical Pulseline Structures for Ion Acceleration," Briggs, Reginato, Waldron, this conference.

• Y.-J. Chen, J.F. McCarrick, S.D. Nelson
  LLNL, Livermore, California

Using the dielectric wall accelerator technology, we are developing of a compact induction accelerator system primarily intended for pulsed radiography. Unlike the typical induction accelerator cell that is long comparing with its accelerating gap width, the proposed dielectric wall induction accelerator cell is short and its accelerating gap width is comparable with the cell length. In this geometry, the rf modes may be coupled from one cell to the next. We will present recent results of rf modeling of the cells and prediction of transverse beam instability on a 2-kA, 8-MeV beam.

• W. J. DeHope, D.A. Goerz, R. Kihara, M.M. Ong, G.E. Vogtlin, J.M. Zentler
  LLNL, Livermore, California

A single-cell test stand has been constructed to facilitate study and guide improvements of the induction electron linac at the FXR radiographic facility at LLNL.* This paper will discuss how modifications in pulse compression and shaping, pulse power transmission, initial ferrite state, and accelerator cell loading have been performed on the test stand and can be applied to the entire accelerator. Some of the specialized diagnostics being used will be described. Finally, the paper will discuss how computer modeling and judicious timing control can be used to optimize accelerator performance by making only selective changes that can be accomplished at minimal cost.

*"Test Stand for Linear Induction Accelerator Optimization," Ong et al., Pulsed Power Conference, June 16, 2003, Dallas TX.

• S.D. Nelson, G.J. Caporaso, A. Friedman, B.R. Poole
  LLNL, Livermore, California
• R.J. Briggs
  SAIC, Alamo, California
• W. Waldron
  LBNL, Berkeley, California

Helix structures have been proposed* for accelerating low energy ion beams using MV/m fields in order to increase the coupling effeciency of the pulsed power system and to tailor the electromagnetic wave propagation speed with the particle beam speed as the beam gains energy. Calculations presented here show the electromagnetic field as it propagates along the helix structure, field stresses around the helix structure (for voltage breakdown determination), optimizations to the helix and driving pulsed power waveform, and simulations showing test particles interacting with the simulated time varying fields.

*"Helical Pulseline Structures for Ion Acceleration," Briggs, Reginato, Waldron, this conference.

• S.D. Nelson, B.R. Poole
  LLNL, Livermore, California

Dielectric Wall Accelerator (DWA) technology incorporates the energy storage mechanism, the switching mechanism, and the acceleration mechanism for electron beams. Electromagnetic simulations of DWA structures includes these effects and also details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam. DWA structures include both bi-linear and bi-spiral configurations with field gradients on the order of 20MV/m and the simulations include the effects of the beampipe, the beampipe walls, the DWA High Gradient Insulator (HGI) insulating stack, wakefield impedance calculations, and test particle trajectories with low emittance gain. Design trade-offs include the transmission line impedance (typically a few ohms), equilibration ring optimization, driving switch inductances, and a layer-to-layer coupling analysis and its affect on the pulse rise time.

• B.R. Poole, S.D. Nelson
  LLNL, Livermore, California
• S. Langdon
  REMCOM Incorporated, State College, Pennsylvania

The modeling of dielectric and magnetic materials in the time domain is required for pulse power applications, pulsed induction accelerators, and advanced transmission lines. For example, most induction accelerator modules require the use of magnetic materials to provide adequate Volt-sec during the acceleration pulse. These models require hysteresis and saturation to simulate the saturation wavefront in a multipulse environment. In high voltage transmission line applications such as shock or soliton lines the dielectric is operating in a highly nonlinear regime, which requires nonlinear models. Simple 1-D models are developed for fast parameterization of transmission line structures. In the case of nonlinear dielectrics, a simple analytic model describing the permittivity in terms of electric field is used in a 3-D finite difference time domain code (FDTD). In the case of magnetic materials, both rate independent and rate dependent Hodgdon magnetic material models have been implemented into 3-D FDTD codes and 1-D codes.

• L. Wang, T.L. Houck, G.A. Westenskow
  LLNL, Livermore, California

An anode stalk support insulator in a magnetically insulated transmission line was designed and modeled. One of the important design criteria is that within space constraints, the electric field along the insulator surface has to be minimized in order to prevent a surface flashover. In order to further reduce the field on the insulator surface, metal rings between insulator layers were also specially shaped. To facilitate the design process, electric field simulations were performed to determine the maximum field stress on the insulator surfaces and the transmission line chamber.

• T. Kikuchi, S. Kawata, T. Someya
  Utsunomiya University, Utsunomiya
• K. Horioka, M. Nakajima
  TIT, Yokohama
• T. Katayama
  CNS, Saitama

• T. Kikuchi, S. Kawata
  Utsunomiya University, Utsunomiya
• K. Horioka
  TIT, Yokohama
• T. Katayama
  CNS, Saitama

• A.A. Malafronte, M.N. Martins
  USP/LAL, Bairro Butantan

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.

• D. Schmied, E. Burtin, P. Guerin, M. Hahn, R. Kersevan
  ESRF, Grenoble

• V. Ayvazyan, G.M. Petrosyan, K. Rehlich, S. Simrock, P. Vetrov
  DESY, Hamburg

• H. Takahashi, Y. Kato, M. Kawase, H. Sako
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• Y. Ito
  Total Saport System Corp., Naka-gun, Ibaraki
• H. Sakaki
  JAERI/LINAC, Ibaraki-ken
• M. Sugimoto
  Mitsubishi Electric Control Software Corp, Kobe
• H. Yoshikawa
  JAERI, Ibaraki-ken

Since the 3GeV RCS produces huge beam power of 1 MW, extreme cares must be taken to design the control system in order to minimize radiation due to beam loss. Another complexity appears in the control system, because each beam bunch of 25 Hz is required to be injected either into the MLF* or into the 50GeV MR.** Therefore, each bunch of 25 Hz must be operated separately, and the data acquisition system must collect synchronized data within each pulse. To achieve these goals, a control system via reflective memory and wave endless recorders has been developed. EPICS is adopted in the control system. Since the number of devices is huge, the management of EPICS records and their configurations require huge amount of time and man power. To reduce this work significantly, a RDB*** for static machine information has been developed. This RDB stores (1) EPICS related information of devices, interfaces, and IOC's**** with a capability to generate EPICS records automatically, and (2) machine geometrical information with a capability to generate lattice files for various simulation applications. The status of the control system focusing on the data acquisition system and the RDB will be presented.

*Material and Life Science Facility. **Main Ring. ***Relational Database. ****Input Output Controller.

• Y. Tanimoto, T. Nogami, T. Obina
  KEK, Ibaraki

• J.C. Yoon, J. Choi, H.-S. Kang, J.-W. Lee
  PAL, Pohang, Kyungbuk

This paper presents the RF control system for Korea Multi-purpose Accelerator Complex (KOMAC). KAERI (Korea Atomic Energy Research Institute) has been performing the project named KOMAC. As the 3nd phase of the project, 20MeV proton accelerating structure is under development. The new design is based on the use of VME based Multi-function modules connected to the specific low level RF Controllers(LLRF) via distributed I/O modules and Serial communication modules. The control system was based on EPICS (Experimental Physics and Industrial Control System) from the end of 2004. Installation and commissioning of the RF module is scheduled on 2005. Control system to integrated the RF System to the KOMAC control system is implemented. Hardware, software and various applications are upgrade to support the operation of RF Control system. In this paper, We describe control structure and scheme of the current RF Control System and upgraded one.

• G.Y. Kurkin
  BINP SB RAS, Novosibirsk
• S.M. Hartman, S. Mikhailov, Y.K. Wu
  DU/FEL, Durham, North Carolina
• I.P. Pinayev
  BNL, Upton, Long Island, New York

A dedicated booster synchrotron is being constructed at the Duke FEL Laboratory to provide full energy injection into the main electron storage ring. A new timing system has been developed to coordinate the injection of electron bunches from the linac to the booster, the ramping of energy in the booster, and extraction of bunches into the main ring. The timing system will allow the extraction of any bunch in the booster into any selected bucket in the main ring to provide top-off injection for any of the various operational bunch patterns of the main ring. A new master oscillator has also been developed for the RF system of the booster. The oscillator may be tuned independently or phase-locked to the master oscillator of the main ring. The issues of the soft phase locking process of the new master oscillator are discussed. The timing system and new oscillator have been fabricated and tested and are ready for operation.

• A.V. Liyu
  RAS/INR, Moscow
• W. Blokland, D.H. Thompson
  ORNL, Oak Ridge, Tennessee

The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based and will run Windows for its OS and LabVIEW as its programming language. Data acquisition hardware will be based on PCI cards. There will be about 300 rack-mounted computers. The Channel Access (CA) protocol of the Experimental Physics and Industrial Control System (EPICS) is the SNS control system communication standard. This paper describes the approaches, implementation, and features of LabVIEW library to CA for Windows, Linux, and Mac OS X. We also discuss how the library implements the asynchronous CA monitor routine using LabVIEW’s occurrence mechanism instead of a callback function (which is not available in LabVIEW). The library is used to acquire accelerator data and applications have been built on this library for console display and data-logging.

• C.R. Chen, F.D. Chang, S.-P. Kao, Joseph. Liu, R.J. Sheu, J.P. Wang
  NSRRC, Hsinchu

• V.P. Suller
  CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
• M.G. Fedurin, P. Jines, D.J. Launey
  LSU/CAMD, Baton Rouge, Louisiana

• R. Soliday
  ANL, Argonne, Illinois

A new Tcl/Tk widget has been created to display MEDM screens inside a Tcl/Tk application. Tcl/Tk parses the MEDM input files and the appropriate widgets are created and linked to the associated process variables. One advantage of this approach is that an X-Windows emulator is not required to view and manipulate the MEDM screen under a Windows operating system. Another benefit is that the MEDM screen can now be tightly integrated into a scripting language to attach higher-level logic to various process variable manipulations. Further details and examples of the new widget will be discussed.

• R. Soliday, M. Borland
  ANL, Argonne, Illinois

Using sddspcas, a portable channel access server that is configured by SDDS input files, it is relatively simple to create process variables (PVs). It can be run in a standalone mode or it can be run so that the PVs are checked to ensure that they don’t conflict with other IOCs or portable channel access servers. It can also be run using the Run Control facility to prevent additional instances of the same sddspcas from being run. The SDDS configuration file provides the PV names, upper and lower limits, units, element counts if the PVs are waveforms, and the types of PVs. Valid types include various precision floats and integers as well as strings. One simple application of this program is that software developers can quickly test their code without requiring the coordination needed to update an IOC database to create PVs. Further details of the features, configuration, and applications of sddspcas will be discussed.

• K.A. Brown, S. Binello, M. Harvey, J. Morris, A. Rusek, N. Tsoupas
  BNL, Upton, Long Island, New York

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. NASA is interested in reproducing the energy spectrum from a solar flare in the space environment for a single ion species. To do this we have built and tested a set of software tools which allow the state of the Booster and the NSRL beam line to be changed automatically. In this report we will desribe the system and present results of beam tests.

• R. H. Carcagno, SF. Feher, M.J. Lamm, A. Makulski, R. Nehring, D.F. Orris, Y.M.P. Pischalnikov, M. Tartaglia
  Fermilab, Batavia, Illinois

• T.L. Allison, T. Powers
  Jefferson Lab, Newport News, Virginia

There are thousands of signals distributed throughout Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) that are useful for troubleshooting and identifying instabilities. Many of these signals are only available locally or monitored by systems with small bandwidths that cannot identify fast transients. The Distributed Data Acquisition (Dist DAQ) system will sample and record these signals simultaneously at rates up to 40 Msps. Its primary function will be to provide waveform records from signals throughout CEBAF to the Experimental Physics and Industrial Control System (EPICS). The waveforms will be collected after the occurrence of an event trigger. These triggers will be derived from signals such as periodic timers or accelerator faults. The waveform data can then be processed to quickly identify beam transport issues, thus reducing down time and increasing CEBAF performance. The Dist DAQ system will be comprised of multiple standalone chassis distributed throughout CEBAF. They will be interconnected via a fiber optic network to facilitate the global triggering of events. All of the chassis will also be connected directly to the CEBAF Ethernet and run EPICS locally. This allows for more flexibility than the typical configuration of a single board computer and other custom printed circuit boards (PCB) installed in a card cage.

allison@jlab.org

• M.E. Bannister, F.W. Meyer, J. W. Sinclair
  ORNL, Oak Ridge, Tennessee

A control system for the 250-kV platform and beamlines for accelerating and transporting multiply-charged ion beams produced by an all-permanent-magnet ECR ion source has been developed at the ORNL Multicharged Ion Research Facility. The system employs Experimental Physics and Industrial Control System (EPICS) software controlling an Allen-Bradley ControlLogix Programmable Logic Controller (PLC). In addition to the I/O control points of the PLC, other devices are controlled directly by the EPICS computer through RS-232 and GPIB interfaces. PLC chassis are located at each major electrical potential of the facility, that is, at the ECR source potential, at the platform potential, and at ground potential used in the beamlines transporting ions to the various experimental end-stations. Connection of the control system components to the EPICS host is accomplished via EtherNet, including fiber optic links to the HV platform. The user interface is designed with the Extensible Display Manager (EDM) software and custom applets perform such tasks as mass-to-charge ratio scans of the platform analyzing magnet and archival of source and beamline operating parameters.

• K. Evans, M. Smith
  ANL, Argonne, Illinois

The EPICS PV Gateway has become a stable, high-performance application that provides access to process variables while minimizing the impact on critical IOCs and implementing additional access security. The additional access security typically prevents write access but is highly configurable. The Advanced Photon Source (APS) currently uses 40 Gateways running on 11 machines to provide access to the machine network from the offices and for the individual experimental teams. These include reverse Gateways that allow administration of all 40 APS Gateways from a single MEDM screen, even though the Gateways are running on separate networks. This administration includes starting, stopping, making and viewing reports, and viewing and editing access security files. There is one Gateway that provides process variable renaming. This paper provides an overview of the Gateways at the APS and describes the procedures that have been set up to use and administer them.

• N. Kamikubota
  KEK, Ibaraki

• S. Peng
  ORNL, Oak Ridge, Tennessee
• L.T. Hoff, K. Smith
  BNL, Upton, Long Island, New York

The low-level RF control system for the SNS Ring differs considerably from that for the Linac. To accommodate requirements for higher data throughput and improved performance the system is based on a PCI Digital Signal Processor (DSP). In accordance with SNS standards, a VME-based PowerPC© is used, but advantage is taken of the on-board PMC slot which houses a Bittware© Hammerhead© PMC card with four AD-21162 DSPs.The EPICS system handles system configuration and data traffic while the DSP performs the low-level RF controls. Protocol and software to support both the PowerPC and the DSP have been developed. This paper presents the system design and initial testing experience.

• J.Y. Tang, J.A. Crandall, P. Ladd, D.C. Williams
  ORNL, Oak Ridge, Tennessee

SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

• J.Y. Tang, A.V. Aleksandrov, M.M. Champion, P.E. Gibson, J.P. Schubert
  ORNL, Oak Ridge, Tennessee
• A. Feschenko, Y. Kiselev, A.S. Kovalishin, L.V. Kravchuk, A.I. Kvasha
  RAS/INR, Moscow

The Resonance Control Cooling System (RCCS) for the warm linac of the Spallation Neutron Source was designed by Los Alamos National Laboratory. The primary design focus was on water cooling of individual component contributions. The sizing the RCCS water skid was accomplished by means of a specially created SINDA/FLUINT model tailored to these system requirements. A new model was developed in Matlab Simulink and incorporates actual operational values and control valve interactions. Included is the dependence of RF input power on system operation, cavity detuning values during transients, time delays that result from water flows through the heat exchanger, the dynamic process of water warm-up in the cooling system due to dissipated RF power on the cavity surface, differing contributions on the cavity detuning due to drift tube and wall heating, and a dynamic model of the heat exchanger with characteristics in close agreement to the real unit. Because of the Matlab Simulink model, investigation of a wide range of operating issues during both transient and steady state operation is now possible. Results of the DTL RCCS modeling are presented

• S.M. Hartman, S. Mikhailov, Y.K. Wu
  DU/FEL, Durham, North Carolina

The Duke FEL is developing a booster synchrotron to provide full energy injection into the Duke electron storage ring. In this paper, we describe the development of the control system for the booster. Requirements include the competing needs of simple and reliable turn-key operation for the machine as a booster; and the sophistication and flexibility of operation of the machine as a storage ring for commissioning, machine studies and as a light source. To simplify operations and machine studies, the high level controls will present the system in terms of the physics quantities of the accelerator, allowing a tight integration between the physics model and the low level hardware control, as we have previously implemented for Duke storage ring.

• S.M. Hartman
  DU/FEL, Durham, North Carolina

We analyze some recent experiences with commercial off the shelf (COTS) I/O hardware modules, comparing manufacturer specifications with our in-house measurements. Discrepancies between quoted specifications and measured performance under accelerator laboratory conditions have been observed. In some cases, design or manufacturing faults have been found which could have impact on the overall performance of the accelerator.

• F. Tamura
  JAERI/LINAC, Ibaraki-ken
• J.C. Chiba, T. Katoh, M. Yoshii
  KEK, Ibaraki

• G. Liu, X. Bao, C. Li, W. Li, J. Wang, Xie. Xie, K. Xuan
  USTC/NSRL, Hefei, Anhui
• J. Li
  DU/FEL, Durham, North Carolina

• W.R. DeVan, S.E. Hicks, G.S. Lawson, W.H. Wagner, D.M. Wantland, E. Williams
  ORNL, Oak Ridge, Tennessee

Work supported by the U.S. Department of Energy under Contract DE-AC05-00OR22725.

• H. Ohgaki
  Kyoto IAE, Kyoto
• Y. Iwasaki, S. Koda, Y. Takabayashi, T. Tomimasu, K. Yoshida
  Saga Synchrotron Light Source, Industry Promotion Division, Saga City
• H. Toyokawa
  AIST, Ibaraki

• G.J. Portmann
  LBNL, Berkeley, California
• W.J. Corbett, A. Terebilo
  SLAC, Menlo Park, California

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.

• J. Buerger, J.A. Dammann, L. Hagge, J.I. Iversen, A. Matheisen, W. Singer
  DESY, Hamburg

• W. Ackermann, T. Weiland
  TEMF, Darmstadt

To guarantee an adequate design and a proper functionality of various machine components it is of great importance to perform detailed studies of charged particle transport. However, it is often not necessary to initiate individual kinetic simulations. When the evolution of integral quantities is of research interest, it is worth treating an investigated particle ensemble as a whole and applying a macroscopic formulation. Using a collision-less kinetic approach, the simplified model is derived from the well-known Vlasov equation. Instead of solving directly this equation, one can use moments of the density function obtained by means of an averaging process. This formalism had been implemented into the beam dynamics simulation program V-Code and a fundamental database of various beam line elements like cavities, drift spaces, solenoids, quadrupoles and steerers was set up. A flexible realization of the C++ code representing the cavities and the drift spaces can be automatically used for an arbitrary order of moments applying a symbolic algebra program. A useful extension to the remaining beam line elements together with appropriate simulation results is presented in the paper.

• M. Cavenago
  INFN/LNL, Legnaro, Padova

Charge breeding, consistiting of injecting singly charged ion into ECRIS(Electron Cyclotron Resonance Ion Sources) to extract an highly charged ion beam, is a promising technique for rare or radioactive ion beam. Efficiency and extracted beam temperature are dominated by the strong collisional diffusion of charged ion inside source. A computer code, named BEAM2ECR, written to simulate details of the injection, ionization, collision and extraction processes is described.* A model of injection plasma sheath and of source fringe field were recently added. Neutral injection is also supported, for comparison with other techniques, like gas feeding or metal vapor injection. Results, clearly favouring near axis injection for most cases are described. Code is written in C-language and possibility of concurrent execution over a Linux cluster was recently added.

*M. Cavenago, O. Kester, T. Lamy and P. Sortais, Rev. Sci. Instrum. 73, 537 (2002).

• G. Robert-Demolaize, R.W. Assmann, S. Redaelli, F. Schmidt
  CERN, Geneva

• A. Adelmann
  PSI, Villigen
• R.D. Ryne, J.M. Shalf, C. Siegerist
  LBNL, Berkeley, California

• A. Adelmann
  PSI, Villigen
• R.D. Ryne, J.M. Shalf, C. Siegerist
  LBNL, Berkeley, California

• D. Sagan
  Cornell University, Department of Physics, Ithaca, New York
• J.C. Smith
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York

A new accelerator design and analysis simulation environment based on the BMAD relativistic charged particle dynamics library is in development at Cornell University. Called TAO (Tool for Accelerator Optimization), it is a machine independent program that implements the essential ingredients needed to solve simulation problems. This includes the ability to: 1. Design lattices subject to constraints, 2. Simulate errors and changes in machine parameters, and 3. Simulate machine commissioning including simulating data measurement and correction. TAO is designed to be easily customizable so that extending it to solve new and different problems is straight forward. The capability to simultaneously model multiple accelerator lattices, both linacs and storage rings, and injection from one lattice to another allows for the design and commissioning of large multi stage accelerators. It can also simultaneously model multiple configurations of a single lattice. Single particle, particle beam and macroparticle tracking is implemented. Use of TAO with both the International Linear Collider and the Cornell Energy Recovery Linac are provided as examples.

• P. Tenenbaum
  SLAC, Menlo Park, California

• M. Borland
  ANL, Argonne, Illinois

The code {\tt elegant} is widely used for simulation of linacs for drivers for free-electron lasers. Less well known is that elegant is also a very capable code for simulation of storage rings. In this paper, we show a newly-developed graphical user interface that allows the user to easily take advantage of these capabilities. The interface is designed for use on a Linux cluster, providing very high throughput. It can also be used on a single computer. Among the features it gives access to are basic calculations (Twiss parameters, radiation integrals), phase-space tracking, nonlinear dispersion, dynamic aperture (on- and off-momentum), frequency map analysis, and collective effects (IBS, bunch-lengthening). Using a cluster, it is easy to get highly detailed dynamic aperture and frequency map results in a surprisingly short time.

• R.W. Garnett, J.A. Billen, T.P. Wangler
  LANL, Los Alamos, New Mexico
• K.R. Crandall
  TechSource, Santa Fe, New Mexico
• P.N. Ostroumov
  ANL, Argonne, Illinois
• J. Qiang, R.D. Ryne
  LBNL, Berkeley, California
• R.C. York, Q. Zhao
  NSCL, East Lansing, Michigan

We are developing multuparticle beam-dynamics simulation codes for RIA driver linac simulations extending from the low-energy beam transport line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles. The codes have physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for handling the effects of machine errors and other off-normal conditions. In this paper we present the status of the work, describe some recent additions to the codes, and show preliminary end-to-end simulation results for a representative driver-linac design.

• H. Shang, M. Borland
  ANL, Argonne, Illinois

Optimization is commonly used in accelerator design to find linear optics solutions. Such optimizations are usually fairly fast as linear optics computations are themselves fast. For high-brightness storage rings, optimization of nonlinear elements (e.g., sextupoles) is also important in obtaining sufficient dynamic aperture. However, this can be very time onsuming as the basic calculations are time consuming. We have developed an efficient parallel Simplex optimizer that runs on a Linux cluster. It can optimize the result of running essentially any program or script that returns a penalty function value. We have used this optimizer with elegant to optimize dynamic aperture of storage ring designs. We discuss the optimization algorithm and performance, design of penalty functions, and optimization results.

• H. Shang, M. Borland
  ANL, Argonne, Illinois

ExperimentDesigner is a Tcl/Tk interface that allows users to easily design and run complicated experiments using a convenient graphical user interface (GUI). Features include: process variable monitoring, which pauses the experiment when values are out of range; user-defined initialization, execution, and finalization sequences; support of complex execution chains containing actions such as setting controls, reading values, running external programs, interacting with the user, etc.; collection of output data for convenient postprocessing; saving and loading of experiment configurations; convenient use of SDDS Toolkit programs; and execution of experiments from the command line without a GUI.

• P. Emma, K.L.F. Bane
  SLAC, Menlo Park, California

Many linear accelerators, such as linac-based light sources and linear colliders, apply longitudinal phase space manipulations in their design, including electron bunch compression and wakefield-induced energy spread control. Several computer codes handle such issues, but most require detailed information on the transverse focusing lattice. In fact, in most linear accelerators, the transverse distributions do not significantly affect the longitudinal, and can be ignored initially. This allows the use of a fast 2D code to study longitudinal aspects without time-consuming considerations of the transverse focusing. LiTrack is based on a 15-year old code (same name) originally written by one of us (KB), which is now a MATLAB-based code with additional features, such as a graphical user interface and output plotting. The single-bunch tracking includes RF acceleration, bunch compression to 3rd order, geometric and resistive wakefields, aperture limits, synchrotron radiation, and flexible output plotting. The code was used to design both the LCLS and the SPPS projects at SLAC and typically runs in <1 minute. We describe the features, show some examples, and provide access to the code.

• E. Schuster
  Lehigh University, Bethlehem, Pennsylvania
• C.K. Allen
  LANL, Los Alamos, New Mexico
• M. Krstic
  UCSD, La Jolla, California