Fermilab, Batavia, USA
INFN-Ferrara, Ferrara, Italy
IHEP Protvino, Protvino, Moscow Region, Russia
PNPI, Gatchina, Leningrad District, Russia
The T-980 bent crystal collimation experiment at the Tevatron has recently acquired substantial enhancements. First, two new crystals - a 16-strip one manufactured and characterized by the INFN Ferrara group and a quasi-mosaic crystal manufactured and characterized by the PNPI group. Second, a two plane telescope with 3 high-resolution pixel detectors per plane along with corresponding mechanics, electronics, control and software has been manufactured, tested and installed in the E0 crystal region. The purpose of the pixel telescope is to measure and image channeled (CH), volume-reflected (VR) and multiple volume-reflected (MVR) beam profiles produced by bent crystals. Third, an ORIGIN-based system has been developed for thorough analysis of experimental and simulation data. Results of analysis are presented for different types of crystals used from 2005 to present for channeling and volume reflection including pioneering tests of two-plane crystal collimation at the collider, all in comparison with detailed simulations.
IIT, Chicago, Illinois, USA
The Muon Ionization Cooling Experiment (MICE) is a demonstration experiment to prove the viability of cooling a beam of muons for use in a Neutrino Factory and Muon Collider. The MICE cooling channel is a section of a modified Study II cooling channel which will provide a 10% reduction in beam emittance. In order to ensure a reliable measurement, we intend to measure the beam emittance before and after the cooling channel at the level of 1%, or an absolute measurement of 0.001. This renders MICE as a precision experiment which requires strict controls and monitoring of all experimental parameters in order to control systematic errors. The MICE Controls and Monitoring system is based on EPICS and integrates with the DAQ, detector, environment, and data monitoring systems. A description of this system, its implementation, and performance during recent muon beam data collection will be discussed.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
UCR, Riverside, California, USA
IIT, Chicago, Illinois, USA
In the Muon Ionization Cooling Experiment (MICE), muons are cooled by passing through material, then through RF cavities to compensate for the energy loss; which reduces the transverse emittance. It is planned to demonstrate longitudinal emittance reduction via emittance exchange in MICE by using a solid wedge absorber in Step IV. Based on the outcome of previous studies, the shape and material of the wedge were chosen. We address here further simulation efforts for the absorber of choice as well as engineering considerations in connection with the absorber support design.
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
ANL, Argonne, USA
Omega-P, Inc., New Haven, Connecticut, USA
Columbia University, New York, USA
Northern Illinois University, DeKalb, Illinois, USA
NSC/KIPT, Kharkov, Ukraine
Recent tests of a two-channel rectangular dielectric lined accelerator structure are described; comparison with theory and related issues are presented. The structure (with channel width ratio 6:1) is designed to have a maximum transformer ratio of ~12.5:1. It operates mainly in the LSM31 mode (~ 30GHz). The dielectric liner is cordierite (dielectric constant ~4.76). The acceleration gradient is 1.2 MV/m for each 10nC of the drive bunch for the first acceleration peak of the wakefield, and 0.92 MV/m for the second peak. The structure is installed into the AWA beam-line (Argonne National Lab) and is excited by a single 10-50nC, 14MeV drive bunch. Both the drive bunch and a delayed witness bunch are produced at the same photocathode. This is the first experiment to test a two-channel dielectric rectangular wakefield device where the accelerated bunch may be continuously energized by the drive bunch. The immediate experimental objective is to observe the energy gain and spread, and thereby draw conclusions from the experimental results and the theory model predictions. The observed energy change of the test bunch might be well explained*.
* G. V. Sotnikov, et al., Advanced Accelerator Concepts: 13th Workshop, Carl B. Schroeder, Wim Leemans and Eric Esarey, editors, AIP Conf. Proc. 1086), pp. 415–420 (AIP, New York, 2009).
Euclid TechLabs, LLC, Solon, Ohio, USA
ANL, Argonne, USA
We report here on the development of THz diamond wakefield structures produced using Chemical Vapor Deposition (CVD) technology*. The diamond structures would be used in a THz generation experiment at the new FACET facility at SLAC. We consider a dielectric based accelerating structure to study of the physical limitations encountered driving >GV/m wakefields in the cylindrical and planar geometries of a dielectric wakefield accelerator (DWA). In a DWA, an ultrashort drive bunch traverses the evacuated central region of the structure, creating Cherenkov wakefields in the dielectric to accelerate a witness bunch. A diamond-based DWA structure will allow a sustained accelerating gradient exceeding breakdown threshold demonstrated with the FFTB experiments**. The electrical and mechanical properties of diamond make it an ideal candidate material for use in dielectric rf structures: high breakdown voltage, extremely low dielectric losses and the highest thermoconductive coefficient available for removing waste heat from the device.
*R. J. Barker et al., Modern Microwave and Millimeter-Wave Power Electronics, IEEE Press/Wiley-Interscience, Piscataway NJ 2005, Chapter 7
**M.C. Thompson et al. Phys. Rev.Lett.100:214801, 2008.
LBNL, Berkeley, California, USA
Tech-X, Boulder, Colorado, USA
Control of injection into a high gradient laser-plasma accelerator is presented using the beat between two ’colliding’ laser pulses to kick electrons into the plasma wake accelerating phase. Stable intersection and performance over hours of operation were obtained using active pointing control. Dependence of injector performance on laser and plasma parameters were characterized in coordination with simulations. By scanning the intersection point of the lasers, the injection position was controlled, mapping the acceleration length. Laser modifications to extend acceleration length are discussed towards production of tunable stable electron bunches as needed for applications including Thomson gamma sources and high energy colliders.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
LNLS, Campinas, Brazil
USTC/NSRL, Hefei, Anhui, People's Republic of China
An S-band cavity BPM is designed for a new injector in National Synchrotron Radiation Laboratory. A re-entrant position cavity is tuned to TM110 mode as position cavity. Theoretical resolution of the BPM is 31 nm. A prototype cavity BPM system is manufactured for cold test. Wire scanning method is used to calibrate the BPM and estimate the performance of the on-line BPM system. Cold test results showed that position resolution of prototype BPM is better than 3 μm. Cross-talk has been detected during the cold test. Racetrack cavity can be used to suppress cross-talk. Ignoring nonlinear effect, transformation matrix is a way to correct cross-talk.
I-Tech, Solkan, Slovenia
NSRRC, Hsinchu, Taiwan
BNL, Upton, Long Island, New York, USA
With accelerated schedules and finite resources the development of a common open source platform for accelerator instrumentation is required. This effort has led to the development of a flexible architecture with clearly defined interfaces. The resulting platform is currently used to implement fast orbit feedback as well as the Beam Position monitors for NSLS-II. The design includes an embedded processor, digital signal processing resources and communications interfaces to controls, the timing system and other devices distributed throughout the accelerator complex. This new architecture promotes customization and design re-use and is presented as an Open Source Hardware development project.
BNL, Upton, Long Island, New York, USA
Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system [1] for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.
BNL, Upton, Long Island, New York, USA
BNL, Upton, Long Island, New York, USA
The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to control and dynamically tune the magnets. The current implementation and results will be presented.
BNL, Upton, Long Island, New York, USA
The use of fluorescent screens for beam profile monitors provides a simple and widely used way to obtain detailed two dimensional intensity maps. For high precision measurements many possible error contributions need to be considered that have to do with properties of the fluorescent screens and of the CCDs. Saturation effects, reflections within and outside the screen, non-linearities, radiation damage, etc are often mentioned. Here we concentrate on an error source less commonly described, namely erroneous baseline subtraction, which is particularly important when fitting projected images. We show computer simulations as well as measurement results having remarkable sensitivity of the fitted profile widths to even partial suppression of the profile baseline data, which often arises from large pixel-to-pixel variations at low intensity levels. Such inadvertent baseline data suppression is very easy to miss as it is usually not obvious when inspecting projected profiles. In this report we illustrate this effect and discuss possible algorithms to automate the detection of this problem as well as some possible corrective measures.
BNL, Upton, Long Island, New York, USA
LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
An internal R&D program has been undertaken at BNL to develop a sub-micron RF Beam Position Monitor (BPM) for the NSLS-II 3rd generation light source that is currently under construction. The BPM R&D program started in August 2009. Successful beam tests were conducted 15 months from the start of the program. The NSLS-II RF BPM has been designed to meet all requirements for the NSLS-II Injection system and Storage Ring. Housing of the RF BPMs in ±0.1C thermally controlled racks provide sub-micron stabilization without active correction. An active pilot-tone has been incorporated to aid long-term (8hr min) stabilization to 200nm RMS.
BNL, Upton, Long Island, New York, USA
JLAB, Newport News, Virginia, USA
Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements.
Fermilab, Batavia, USA
CERN, Geneva, Switzerland
ESS, Lund, Sweden
SLAC, Menlo Park, California, USA
Fermilab, Batavia, USA
A console application using the phasing of Turn-by-Turn signals from the different BPMs has been tested at the Fermilab Booster. This techinique allows the on-line detection of the beam tunes during the fast Booster ramp in conditions where other algorithms were unsuccessful. The application has been recently expanded to include the computation of the linear coupling coefficients. Algorithm and measurement results are presented.
Fermilab, Batavia, USA
Ionization profile monitors (IPMs) are used in the Fermilab Main Injector (MI) for injection lattice matching and to measure transverse emittance of the beam during acceleration. The IPMs provide a periodic, non-destructive means for emittance measurements where other techniques are not applicable. As Fermilab is refocusing its attention on the intensity frontier, non-intercepting diagnostics such as IPMs are expected to become even more important. This paper gives an overview of the operational use of IPMs for emittance measurements and injection lattice matching measurements at Fermilab, and summarizes the future plans.
Fermilab, Batavia, USA
The Fermilab A0 Photoinjector is a 16MeV high intensity, high brightness electron Linac developed for advanced accelerator R&D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties.
URS, Albuquerque, New Mexico, USA
LANL, Los Alamos, New Mexico, USA
A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments cRIO module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal data-acquisition system, and wire bias of 0V to ±50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.
URS, Albuquerque, New Mexico, USA
LANL, Los Alamos, New Mexico, USA
The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wire-scanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sense-wire interface with variable DC wire bias and wire-integrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel.
LANL, Los Alamos, New Mexico, USA
New beam-position and phase monitors are under development for the linac at the Los Alamos Neutron Science Center. Transducers have been designed and are being fabricated. We are considering many options for the electronic instrumentation to process the signals and provide position and phase data with the necessary precision and flexibility to serve the various required functions. We’ll present the requirements of the system and the various options under consideration for instrumentation along with the advantages and shortcomings of these options.
LANL, Los Alamos, New Mexico, USA
URS, Albuquerque, New Mexico, USA
The Beam Diagnostics and Instrumentation Team at Los Alamos National Laboratory’s LANSCE facility is presently developing a new and improved wire scanner diagnostics system controlled by National Instrument’s cRIO platform. This report describes the current state of development of the control system along with the results gathered from the latest actuator motion performance and accelerator beam data acquisition tests.
BNL, Upton, Long Island, New York, USA
Testing a single hardware unit of an accelerator control system often requires the setup of a graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all testing and control logic. The third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.
BNL, Upton, Long Island, New York, USA
Power Supply checkout is a necessary, pre-beam, time-critical function. At odds are the desire to decrease the amount of time to perform the checkout while at the same time maximizing the number and types of checks that can be performed and analyzing the results quickly (in case any problems exist that must be addressed). Controls and Power Supply Group personnel have worked together to develop tools to accomplish these goals. Power Supply checkouts are now accomplished in a time-frame of hours rather than days, reducing the number of person-hours needed to accomplish the checkout and making the system available more quickly for beam development.
BNL, Upton, Long Island, New York, USA
An alarm system is a vital component of any accelerator, as it provides a warning that some element of the system is not functioning properly. The severity and age of the alarm may sometimes signify whether urgent or deferred attention is required. For example, older alarms may inadvertently be given a lower priority if an assumption is made that someone else is already investigating it, whereas those that are more current may indicate the need for an immediate response. The alarm history also provides valuable information regarding the functionality of the overall system, thus careful tracking of these data is likely to improve response time and remove uncertainty about the current status. Since one goal of every alarm display is to be free of alarms, a clear and concise presentation of an alarm along with useful historic annotations can help the end user address the warning more quickly. By defining a discrete set of very specific alarm states and by utilizing database resources to maintain a complete and easily accessible alarm history, we anticipate a decrease in down time due to more efficient operator response and management of alarms.
BNL, Upton, Long Island, New York, USA
The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes a detailed client API design, and latest progress.
BNL, Upton, Long Island, New York, USA
The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. The server development is ongoing, and adopts a sourceforge open project so-called epics-pvdata, which consists of pvData, pvAccess, pvEngine, and pvService. Some services have being demonstrated as one service under pvService module such as itemFinder service, gather service, and lattice manager, and each service runs as one standalone server using pvData to store in-memory transient data, pvService to transfer data over network, and pvEngine as service engine. This paper describes a detailed development, latest progress, and performance analysis.
LANL, Los Alamos, New Mexico, USA
Los Alamos National Laboratory LANL is in the process of upgrading the control system for the Los Alamos Neutron Science Center (LANSCE) linear accelerator. The 38 year-old data acquisition and control equipment is being replaced with COTS hardware. An overview of the current system requirements and how the National Instruments cRIO system meets these requirements will be given, as well as an update on the installation and operation of a prototype system in the LANSCE LINAC.
LANL Release Number: LA-UR 10-06605
ORNL, Oak Ridge, Tennessee, USA
The SNS has been successfully operating 81 superconducting six-cell cavities in 23 cryomodules in its linac to achieve the goals in beam power and energy. For near-term production of spare cryomodules and the upcoming power upgrade project that will need 36 additional cavities in 9 cryomodules, high RF power testing and qualification of the cavities is required in the RF test facility. Simultaneously powering all the cavities in a cryomodule is considered desirable for robust conditioning and studying of cavity field emission since certain cavities exhibit field emissions that could be mutually coupled. A four-way variable output power waveguide splitting system is being prepared for testing cryomodules with up to four cavities. The splitting system is fed by an 805 MHz, 5 MW peak power pulsed klystron. The power output at each arm can be adjusted in both amplitude and phase to wide ranges of values using two mechanical waveguide phase shifters that form a vector modulator. The system control is implemented in the EPICS environment similar to the main accelerator controls. The work performed on the design, integration, operation, and test of the system are presented.
JLAB, Newport News, Virginia, USA
With inauguration of the CEBAF Element Database(CED) in Fall 2010, Jefferson Lab computer scientists have taken a first step toward the eventual goal of a model-driven accelerator. Once fully populated, the database will be the primary repository of information used for everything from generating lattice decks to booting iocs to building controls screens. A requirement influencing the CED design is that it provide access to not only present, but also future, and eventually past, configurations of the accelerator. To accomplish this, an introspective database schema was designed that allows new elements, types, and properties to be defined on-the-fly with no changes to table structure. Used in conjunction with Oracle Workspace Manager, it allows users to query data from any time in the database history with the same tools used to query the present configuration. Users can also check-out workspaces to use as staging areas for upcoming machine configurations. All Access to the CED is through a well-documented API that is translated automatically from original C++ into native libraries for script languages such as perl, php, and TCL making access to the CED easy and ubiquitous.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.
LNLS, Campinas, Brazil
BNL, Upton, Long Island, New York, USA
Vibrations of the cryogenic triplet magnets at the Relativistic Heavy Ion Collider (RHIC) are suspected to be causing the beam perturbations observed at frequencies around 10 Hz. Several solutions to counteract the effect have been considered in the past, including reinforcing the magnet base support assembly, a mechanical servo feedback system, and a local beam feedback system at each of the two experimental areas. However, implementation of the mechanical solutions would be expensive, and the local feedback system was insufficient since perturbation amplitudes outside the experimental areas were still problematic. A global 10 Hz orbit feedback system is currently under development at RHIC consisting of 36 beam position monitors (BPMs) and 12 small dedicated dipole corrector magnets in each of the two counter-rotating rings. A subset of the system consisting of 8 BPMs and 4 corrector magnets in each ring was installed and successfully tested during the RHIC 2010 run; and the complete system is being installed for the 2011 run. A description of the overall system architecture and results with beam will be discussed.
BNL, Upton, Long Island, New York, USA
The shielding design for the NSLS-II storage ring is designed for the full injected beam losses in two periods of the ring around the injection point, but for the remainder of the ring its shielded for <10% top-off injection beam. This will require a system to insure that beam losses do not exceed these levels for time sufficient to cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring (LCM) system will control the beam losses to the more heavily shielded injection region while monitoring the losses outside this region. To achieve this scrapers are installed in the injection region to intercept beam particles that might be lost outside this region. The scrapers will be thin (< 1Xrad) that will allow low energy electrons to penetrate and the subsequent dipole will separate them from the stored beam. These thin scrapers will reduce the radiation from the scraper compared to thicker scrapers. The dipole will provide significant local shielding for particles that hit inside the gap and a source for the loss monitor system that will measure the amount of beam lost in the injection region.
* Beam Loss Monitors for NSLS-II Storage Ring, S.L. Kramer & P. Cameron, these proceedings
BNL, Upton, Long Island, New York, USA
The Machine Protection System (MPS) is a device-safety system that is designed to prevent damage to hardware by generating interlocks, based upon the state of input signals generated by selected sub-systems. It protects all the key machinery in the R&D Project called the Energy Recovery LINAC (ERL) against the high beam current. The MPS is capable of responding to a fault with an interlock signal within several microseconds. The ERL MPS is based on a National Instruments CompactRIO platform, and is programmed by utilizing National Instruments' development environment for a visual programming language. The system also transfers data (interlock status, time of fault, etc.) to the main server. Transferred data is integrated into the pre-existing software architecture which is accessible by the operators. This paper will provide an overview of the hardware used, its configuration and operation, as well as the software written both on the device and the server side.
TUB, Beijing, People's Republic of China
LBNL, Berkeley, California, USA
BNL, Upton, Long Island, New York, USA
A critical capability of the new RHIC low level rf system is the ability to synchronize signals across multiple locations. The Update Link provides this functionality. The Update Link is a deterministic serial data link based on the Xilinx Aurora protocol that is broadcast over fiber optic cable at 1 gigabit per second. The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources.
BNL, Upton, Long Island, New York, USA
The RHIC LLRF platform is a flexible, modular system designed around a carrier board with six XMC daughter sites. The carrier board features a Xilinx FPGA with an embedded, hard core Power PC that is remotely reconfigurable. It serves as a front end computer (FEC) that interfaces with the RHIC control system. The carrier provides high speed serial data paths to each daughter site and between daughter sites as well as four generic external fiber optic links. It also distributes low noise clocks and serial data links to all daughter sites and monitors temperature, voltage and current. To date, two XMC cards have been designed: a four channel high speed ADC and a four channel high speed DAC.
BNL, Upton, Long Island, New York, USA
The RHIC LLRF upgrade is a flexible, modular system. Output signals are generated by a custom designed XMC card with 4 high speed digital to analog converters interfaced to a high performance field programmable gate array (FPGA). This paper discusses the hardware details of the XMC DAC board as well as the implementation of a low noise rf synthesizer with digital IQ modulation. This synthesizer also provides injection phase cogging and frequency hop rebucketing capabilities.
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
CLASSE, Ithaca, New York, USA
TUL-DMCS, Łódź, Poland
The Advanced Telecommunications Computing Architecture (ATCA), MicroTCA (uTCA) and Advanced Mezzanine Card (AMC) standards, known as xTCA, provide unique features desired by various control systems of particle accelerators. The standards provide availability and operability as high as 99.999 %. A significant number of additional features must be implemented to take a full advantage of xTCA standards and gain the required availability. On the other hand, many control systems require various data acquisition and control modules with different number of input analogue and digital inputs or outputs as defined by their respective system specifications. The paper presents an universal base module, designed according to the AMC standard with an FPGA Mezzanine Card connector, that can be used for fast development of input-output subsystems. The module consists of two submodules. The digital part is designed according to the AMC standard while the main input-output functionality is realized by the FPGA Mezzanine Card part. The FMC submodule provides the functionality required by the specification of the LLRF system.
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
TUL-DMCS, Łódź, Poland
DESY, Hamburg, Germany
BNL, Upton, Long Island, New York, USA
A digital low-level radio frequency (LLRF) field controller has been developed for the storage ring of The National Synchrotron Light Source-II (NSLS-II). The primary performance goal for the LLRF is to support the required RF operation of the superconducting cavities with a beam current of 500mA and a 0.14 degree or better RF phase stability. The digital field controller is FPGA-based, in a standard format 19”/1-U chassis. It has an option of high-level control support with MATLAB running on a local host computer through a USB2.0 port. The field controller has been field tested with the high-power superconducting RF (SRF) at Canadian light Source, and successfully stored a high beam current of 250 mA. The test results show that required specifications for the cavity RF field stability are met. This digital field controller is also currently being used as a development platform for other functional modules in the NSLS-II RF systems.
BNL, Upton, Long Island, New York, USA
A high performance FPGA based platform has been developed for the RHIC Low Level RF system upgrade, and is now replacing our aging VME based systems. This new platform employs a sophisticated embedded architecture to implement its core functionality. This architecture provides a control system interface, manages remote access to all configuration parameters and diagnostic data, supports communication between all system components, enables real time application specific processing, monitors system health, etc. This paper will describe the embedded architecture and its capabilities, with emphasis on its application at RHIC.
BNL, Upton, Long Island, New York, USA
As part of the overall development effort for the RHIC LLRF Upgrade Platform, a 4 channel ADC daughter module was developed to provide high speed, wide dynamic range digitizing and processing of signals from DC to several hundred megahertz. The first operational use of this card was to implement the bunch to bucket phase detector for the RHIC LLRF beam control feedback loops. This paper will describe the design and performance features of this daughter module as a bunch to bucket phase detector, and also provide an overview of its place within the overall LLRF platform architecture as a high performance digitizer and signal processing module suitable to a variety of applications.
BNL, Upton, Long Island, New York, USA
During RHIC Run 10, the first phase of the LLRF Upgrade was successfully completed. This involved replacing the aging VME based system with a modern digital system based on the recently developed RHIC LLRF Upgrade Platform, and commissioning the system as part of the normal RHIC start up process. At the start of Run 11, the second phase of the upgrade is underway, involving a significant expansion of both hardware and functionality. This paper will review the commissioning effort and provide examples of improvements in system performance, flexibility and scalability afforded by the new platform.
BNL, Upton, Long Island, New York, USA
The Electron Beam Ion Source (EBIS) LLRF system utilizes the RHIC LLRF upgrade platform to achieve the required functionality and flexibility. The LLRF system provides drive to the EBIS high-level RF system, employs IQ feedback to provide required amplitude and phase stability, and implements a cavity resonance control scheme. The embedded system provides the interface to the existing Controls System, making remote system control and diagnostic possible. The flexibility of the system allows us to reuse VHDL codes, develop new functionalities, improve current designs, and implement new features with relative ease. In this paper, we will discuss the commissioning process, issues encountered, and performance of the system.
ORNL, Oak Ridge, Tennessee, USA
ORNL RAD, Oak Ridge, Tennessee, USA
CLASSE, Ithaca, New York, USA
KEK, Ibaraki, Japan
USC, Los Angeles, California, USA
BNL, Upton, Long Island, New York, USA
We present initial experimental results showing the excitation of plasma wakefields by a train of two drive bunches. These wakefields are experienced by a trailing witness bunch that gains energy while retaining a finite energy spread. These well controlled plasma wakefield accelerator (PWFA) experiments are important to test the theory of the PWFA and serve as a testbed for techniques that will be used in high energy experiments.
ANL, Argonne, USA
Optimization through simulation is a time-consuming task in accelerator design, especially for high dimensional problems. We explored several parallel optimization techniques, including Parallel Genetic Algorithm (PGA), Hybrid Parallel Simplex (HPS), and Parallel Particle Swarm Optimization (PPSO), to solve some real world problems. The serial simplex method in elegant was used as a benchmark for newly-developed parallel optimization algorithms in Pelegant. PGA and HPS are not faster than the serial simplex method, but they more reliably find the global optimum. PPSO is well suited for parallel computing, allowing significantly faster turn-around given sufficient computing resources. Parallel optimization implementations in Pelegant thus promise to not only make optimization results more reliable, but also open the possibility of fast, "real time" optimization of complex problems for accelerator operation.
Fermilab, Batavia, USA
RRCAT, Indore (M.P.), India
Fermilab, Batavia, USA
IIT, Mumbai, India
IUAC, New Delhi, India
Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
TUL-DMCS, Łódź, Poland
The linear accelerators applied to drive Free Electron Lasers (FELs), such as the X-Ray Free Electron Laser (XFEL), require sophisticated control systems. The Low Level Radio Frequency (LLRF) control systems of a linear accelerator should provide signal to vector modulator in less than 1 microsecond. Therefore the latency of communication interfaces is more important than their throughput. The paper discusses the application of serial gigabit links for transmission of data in LLRF systems. The latency of pure serial transmission based on Xilinx RocketIO transceivers was evaluated and compared with Xilinx Aurora protocol. The developed low latency protocol will be also presented.
TUL-DMCS, Łódź, Poland
In this article an asset management application for a low level radio frequency (LLRF) control system is described. The system was developed to facilitate management of some aspects of controlling a linear accelerator and, among others, provides means to manage and program multiple firmware versions for a large, distributed and frequently changing set of FPGA devices that are present in a control system. The system introduces a multihierarchical tree-based representation of almost all assets involved in accelerator management.*
* Kamiński M., Makowski D., Mazur P., Murlewski J., Sakowicz B.: "Firmware application for LLRF control system based on the Enterprise Service Bus", CADSM 2009, Ukraine, ISBN 978-966-2191-05-9
ESS Bilbao, Bilbao, Spain
UPV-EHU, Leioa, Spain
Bilbao, Faculty of Science and Technology, Bilbao, Spain
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
ESS-Bilbao, Zamudio, Spain
Elytt Energy, Madrid, Spain
BNL, Upton, Long Island, New York, USA
AES, Medford, NY, USA
The 703MHz superconducting gun will have 2 fundamental power couplers (FPCs). Each FPC will deliver up to 500kW of RF power. In order to prepare the couplers for high power RF service and process multipacting, the FPCs should be conditioned before they are installed in the gun. A conditioning cart based test stand, which includes a vacuum pumping system, controllable bake-out system, diagnostics, interlocks and data log system has been designed, constructed and commissioned by collaboration of BNL and AES. This paper presents FPC conditioning cart systems and summarizes the conditioning process and results.
Euclid TechLabs, LLC, Solon, Ohio, USA
Fermilab, Batavia, USA
* P. Avrakhov, et al, Phys. of Part. and Nucl. Let, 2008, Vol. 5, No. 7, p. 597
** G. Wu, et al, IPAC 2010, THPD048
Fermilab, Batavia, USA
Yale University, Physics Department, New Haven, CT, USA
Euclid TechLabs, LLC, Solon, Ohio, USA
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
* A. Kanareykin, et al, IPAC 2010, p. 3987
** S. Kazakov, et al, “Fast Ferroelectric Phase Shifter Design For ERLs,” 45th ICFA Beam Dynamics Workshop, 2009
*** S. Kazakov, et al, PAC2007, p. 599.
Fermilab, Batavia, USA
Fermilab is developing 325 MHz SRF spoke cavities for the proposed ProjectX. A compact fast/slow tuner has been developed to compensate microphonics and Lorentz force detuning. The modified tuner design and results of 4K tests of the first prototype are presented.
Fermilab, Batavia, USA
INFN/LASA, Segrate (MI), Italy
Fermilab is building Cryomodule 2 for ILCTA facility at NML. A coaxial blade tuner has been chosen for the CM2 1.3GHz SRF cavities. A summary of results from cold test of the tuners in the Fermilab Horizontal Test Stand will be presented.
Fermilab, Batavia, USA
Muons, Inc, Batavia, USA
In order to make use of ferrite and/or garnet materials in the phase and frequency locked magnetron, for which Muons, Inc., received a Phase II award, materials must be tested in two orthogonal magnetic fields. One field is from the biasing field of the magnetron, the other from the biasing field used to control the ferrite within the anode structure of the magnetron. A test fixture was built and materials are being tested to determine their suitability. The status of those material tests are reported on in this paper.
Fermilab, Batavia, USA
The proposed multi-MW Project X facility at Fermilab will employ cavities with bandwidths as narrow as 20 Hz. This combination of high RF power with narrow bandwidths combined requires careful attention to detuning control if these cavities are to be operated successfully. Detuning control for Projects X will require a coordinated effort between the groups responsible for various machine subsystems. Considerable progress in this area has been made over the past year.
Tomco Technologies, Stepney, South Australia, Australia
Siemens AG, Erlangen, Germany
Siemens AG, Healthcare Technology and Concepts, Erlangen, Germany
* Heid O., Hughes T. THPD002, IPAC10, Kyoto, Japan
** Hergt M et al, 2010 IEEE International Power Modulator and High Voltage Conf., Atlanta GA, USA
*** Heid O., Hughes T. THP068, LINAC10, Tsukuba, Japan
ANL, Argonne, USA
Development and testing of a prototype 352-MHz, 4-kW cw solid state rf power amplifier system is underway at the Advanced Photon Source to study and evaluate the performance advantages of an upgrade to solid state rf power technology at the APS. General performance measurement data on the assembled amplifier system is discussed, with emphasis on efficiency improvements possible through the use of dynamic drain voltage control.
DULY Research Inc., Rancho Palos Verdes, California, USA
Marx modulators, promising higher efficiency, longer lifetime and reduced cost compared with existing hard tube modulator options, are under intensive research. In this article, we describe the progress of work on our voltage droop compensation scheme for a Marx modulator. Experimental results on a compensation circuit at moderate voltage are presented.
LANL, Los Alamos, New Mexico, USA
Compa Industries, Inc., Los Alamos, New Mexico, USA
A Full-scale prototype of a new 201 MHz RF Final Power Amplifier (FPA) for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, assembled and installed in the test facility. This prototype was successfully tested and met the physics and electronics design criteria. With a goal to produce 3.2 MW peak power at 15% duty factor, at the elevation of over 2 km in Los Alamos, The team faced design and manufacturing challenges. The mechanical design of the final power amplifier was built around a Thales TH628 Diacrode®, a state-of-art tetrode power tube*. The main structure includes Input circuit, Output circuit, Grid decoupling circuit, Output coupler, Tuning pistons, and a cooling system. Many kinds of material were utilized to make this new RF amplifier. The FPA is nearly 1000 kg and installed in a beam structural support stand. In this paper, we summarize the FPA design basis and fabrication, plating, and assembly process steps with necessary lifting and handling fixtures. In addition, to ensure the quality of the FPA support structure a finite element analysis with seismic design forces has also been carried out.
* J. Lyles, S. Archuletta, N. Bultman, Z. Chen, et al., “Design of a New VHF RF Power Amplifier System for LANSCE”, IPAC’10, Kyoto, Japan, May 24-28, 2010.
LANL, Los Alamos, New Mexico, USA
Compa Industries, Inc., Los Alamos, New Mexico, USA
Texas A&M University, College Station, Texas, USA
A new test facility was designed and constructed at Los Alamos Neutron Science Center (LANSCE) for testing the Thales TH628 Diacrode® and TH781 tetrode power amplifiers. Anode power requirements for the TH628 are 28 kV DC, with peak currents of 190 Amperes in long pulses. A new 225 uF capacitor bank supplies this demand. A charging power supply was obtained by re-configuring a 2 MW beam power supply remaining from another project. A traditional ignitron crowbar was designed to rapidly discharge the 88 kJ stored energy. The anode power supply was extensively tested using a pulsed tetrode switch and resistor load. A new Fast Protect and Monitor System (FPMS) was designed to take samples of RF reflected power, anode HV, and various tube currents, with outputs to quench the HV charging supply, remove RF drive and disable the conduction bias pulse to the grid of each tube during fault events. The entire test stand is controlled with a programmable logic controller, for normal startup sequencing and timing, protection against loss of cooling, and operator GUI.
BNL, Upton, Long Island, New York, USA
Meyer Tool & MFG, Oak Lawn, Illinois, USA
Texas A&M University, College Station, Texas, USA
TAMU3 is a block-coil short model dipole which embodies for the first time at high field (>12T) strength the techniques of stress management within the superconducting windings. The dipole consists of two planar racetrack coil assemblies, assembled within the rectangular aperture of a flux return core. Each assembly contains an inner and outer winding, and a high-strength support structure which is integrated within the assembly to intercept the Lorentz stress produced from the inner winding so that it does not accumulate to produce high stress in the outer winding. Iso-static preload is applied by pressurizing a set of thin stainless steel bladders with molten Woods metal and then freezing the metal under pressure. Current technology, difficulties, and present status of construction of magnet assembly will be presented.
FHNW, Windisch, Switzerland
In particle accelerators, the magnet power supply system (controller, power stage and magnet) normally has a higher system order (>5). An exact model, representing the behavior of such a system, would be very helpful for an optimal control. For the control, the engineers are mainly not interested in the analytic model, which shows the exact internal mechanisms of the physical system, but, in a model describing the I/O behavior. Moreover, since the real elements do not exactly correspond to the design values, it is desirable to model the power supply system by means of system identification from measured properties. For that, a subspace based identification method is applied, which yields the observer for the self-optimizing high dynamic control of magnet power supplies at the Paul Scherrer Institute (PSI). The only inputs the identification needs are the measured DC-link voltage, the magnet voltage and the magnet current. With that it calculates a corresponding state space model for the system. The whole process is done automatically and in situ, which is a practical and meaningful approach to obtain the exact system information for control design.
FHNW, Windisch, Switzerland
PSI, Villigen, Switzerland
In 1999, the first fully digitally controlled magnet power supplies were put into operation at PSI (Paul Scherrer Institute, Switzerland). Today, approximately 1000 are in use at PSI and a multiple of that worldwide. This project aims at developing a high performance control scheme for a better dynamic behavior of today's magnet powers supplies, without reducing their excellent static behaviors. The resulting control strategy, an in situ identification based observer, combined with state space and proportional integral (SS-PI) control, leads to a significantly improved dynamic behavior of the existing power supplies. The whole commissioning, including system identification, as well as control parameter determination and optimization, is done automatically on the DSP with support of a PC. The control strategy has been implemented on the existing PSI controller and a 10A-corrector power supply, together with various magnets, by updating the software and/or firmware only. Currently, the new control strategy is being implemented and tested at PSI on a second generation Digital Power Electronic Control System (DPC) controller card.
ANL, Argonne, USA
ANL, Argonne, USA
The APS booster is a 7-GeV electron synchrotron with 0.5-second cycle time. Both voltage and current ramp modes were in the original design but only the voltage ramp has been commissioned. Two software-based ramp control programs are used to regulate the current waveform to a linear ramp. The system has been operated for user beam operations for many years. Some instability exists in the ramp correction that requires manual intervention from time to time by the operators. Sensitivity of magnet currents to external changes, such as AC line voltage, harmonic interference from the high-power rf system, etc., has been observed. In order to meet the increased single-bunch-charge requirement of the APS upgrade we need more flexible current ramps such as flat porches for injection and extraction and smooth transitions. Recent efforts to develop an energy-saving operation mode also call for ramp improvement. This paper presents test results of a workstation-based current regulation program and an FPGA-based implementation as a future upgrade.
BNL, Upton, Long Island, New York, USA
The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, ±2000 Volts, or 3000 Amps, ±6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the different modes of operation of the power supply. Since the power supply has been in operation for the last 18 years, upgrading this power supply is essential. A new power supply topology has been studied where energy is stored in capacitor banks. DC to DC converters are used to convert the dc voltage stored in the capacitor banks to pulsed DC voltage into the magnet load. This enables the average incoming power from the ac line to be constant while the peak magnet power is pulsed to ± 18 MWatts. Simulations and waveforms of this power supply will be presented.
BNL, Upton, Long Island, New York, USA
LBNL, Berkeley, California, USA
The Advanced Light Source (ALS) is a third generation synchrotron light source that has been operating since 1993 at Berkeley Lab. A few years ago, the ALS was upgraded to achieve Top-Off Mode, which required replacing the booster dipole and quadrupole magnet power supplies to increase the peak booster beam energy from 1.5GeV to 1.9GeV. The original analog controller for each power supply has been replaced by a digital power supply controller (DPSC) to improve stability and resolution and provide a remote interface. The DPSC capabilities include 24-bit 100k-point digital reference waveform download and voltage reference generation, and complete digital current loop implementation. The hardware includes an FPGA with an embedded processor running a full EPICS IOC on VxWorks. This paper will present the current functionality of the DPSC as well as performance results from recent commissioning.
SLAC, Menlo Park, California, USA
The SLAC P2 MARX P2 Modulator consists of 32 cells charged in parallel by a -4000V supply and discharged in series to provide a -120 KV 140 amp 1.6 millisecond pulse. Each cell has a 350uF main storage capacitor. The voltage on the capacitor will droop approximately 640 volts during each pulse. Each cell will have a boost supply that can add up to 700V to the cell output. This allows the output voltage of the cell to remain constant within 0.1% during the pulse. The modulator output voltage control is determined by the -4KV charging voltage. A voltage divider will measure the modulator voltage on each pulse. The charging voltage will be adjusted by the data from previous pulses to provide the desired output. The boost supply in each cell consists of a 700V buck regulator in series with the main capacitor. The supply uses a lookup table for PWM control. The lookup table is calculated from previous pulse data to provide a constant cell output. The paper will describe the modulator and cell regulation used by the MARX modulator. Measured data from a single cell and three cell string will be included.
BNL, Upton, Long Island, New York, USA
We designed two electron lenses to apply head-on beam-beam compensation for RHIC; they will be installed near IP10. The electron-beam transport system is an important subsystem of the entire electron-lens system. Electrons are transported from the electron gun to the main solenoid and further to the collector. The system must allow for changes of the electron beam size inside the superconducting magnet, and for changes of the electron position by 5 mm in the horizontal- and vertical-planes.
NSRRC, Hsinchu, Taiwan
NSRRC, Hsinchu, Taiwan
BNL, Upton, Long Island, New York, USA
A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT® model, which simulated the 4.5K/ 4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.
BNL, Upton, Long Island, New York, USA
A small cryogenic system and warm helium vacuum pumping system provides cooling to the Energy Recovery Linac's (ERL) cryomodules, a 5-cell cavity and an SRF gun, and a large Vertical Test Dewar. The system consist of a model 1660S PSI (KPS) plant, a 4000 liter storage dewar, subcooler, wet expander, 50 g/s main helium compressor and 170 m3 storage tank. A system description and operating plan is given of the cryogenic plant and cryomodules
BNL, Upton, Long Island, New York, USA
In order to cool the superconducting magnets in RHIC, its helium refrigerator distributes 4.5 K helium throughout the tunnel via a series of distribution and return lines. The worst case for failure would be a release from the magnet distribution line, which operates at 3.5 to 4.5 atmospheres and contains the energized magnet bus. Should the bus insulation system fail or an electrical connection open, there is the potential for releasing up to 70 MJoules of stored energy. Studies were done to determine release rate of the helium and the resultant reduction in O2 concentration in the RHIC tunnel and service buildings. Equipment and components were also reviewed for reliability and the effects of 10 years of operations. Modifications were made to reduce the likelihood of failure and to reduce the amount of helium gas that could be released into tunnels and service buildings while personnel are present. This paper describes the issues reviewed, the steps taken, and remaining work to be done to reduce the hazards.
BNL, Upton, Long Island, New York, USA
Advanced Design Consulting, Inc, Lansing, New York, USA
BNL, Upton, Long Island, New York, USA
A horizontal tune jump system has been installed to overcome the horizontal intrinsic spin resonances, which requires jumping the horizontal tune 0.04 units 82 times, 41 up and 41 down. Two quadruple magnets have been installed in AGS ring to do this. The pulsed magnet currents range from about 140 amps near injection to about 1400 amps late. Current pulse rise and fall times are around 100 micro-sec and flat tops time are around 4mS. These quadruples have separate supplies. This tune jump pulse power supply employees all semiconductor parts as the main switches. During dummy load and magnet testing, the test result showed that the power supply could meet the specification. This article will describe some detail of power supply simulation, design and testing. Some test waveform and pictures are presented in this paper.
Diversified Technologies, Inc., Bedford, Massachusetts, USA
Diversified Technologies, Inc., Bedford, Massachusetts, USA
Rockfield Research, Inc. east, Winchester, Massachusetts, USA
Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator. The modulator is designed for high efficiency in the 100 kV to 500 kV range, for currents up to 500 A, pulse lengths of 0.2 to 5.0 μs, and risetimes <300 ns. Key objectives of the development effort are modularity and scalablity, combined with low cost, and ease of manufacture. For short-pulse modulators, this Marx topology provides a means to achieve fast risetimes and flattop control that are simply not available with hard switch or transformer-coupled topologies. In this paper, DTI will describe the new design and provide an update on progress.
SLAC, Menlo Park, California, USA
The SLAC P2 Marx is under development for the ILC linac klystron modulator. Specifications are for an output of 120 kV, 140 A, 1.6 ms pulse width, 5 Hz pulse repetition frequency, and ± 0.5% flat-top. The SLAC P2 Marx builds upon the success of the P1 Marx, which is currently undergoing lifetime evaluation. While the P2 Marx’s target application is the ILC, characteristics of the Marx topology make it equally well-suited for different parameter ranges; for example, increased pulse repetition frequency, increased output current, longer pulse width, etc. Marx parameters such as the number of cells, cell capacitance, and component selection can be optimized for the application. This paper provides an overview of the P2 Marx development including design, fabrication progress, and test results for the modulator and sub-assemblies. High-availability features of the modulator such as the diagnostic/prognostic embedded control system and fault-adaptive automatic reconfiguration will be detailed. In addition, the scalability of the Marx topology to other long-pulse parameter ranges will be highlighted. Topology adaptations for several proposed accelerators will be presented.
LANL, Los Alamos, New Mexico, USA
There are several refurbishment projects underway at the Los Alamos National Laboratory LANSCE linear accelerator. Systems involved are: RF, water cooling, networks, diagnostics, timing, controls, etc. The Drift Tube Linac (DTL) portion of the accelerator consists of four DTL tanks, each with three independent water control systems. The systems are about 40 years old, use outdated and non-replaceable equipment and NIM bin control modules, are beyond their design life and provide unstable temperature control. Insufficient instrumentation and documentation further complicate efforts at maintaining system performance. Detailed design of the replacement cooling systems is currently in progress. Previous design experience on the SNS accelerator water cooling systems will be leveraged. Plans call for replacement of water piping, manifolds, pumps, valves, mix tanks, instrumentation (flow, pressure and temperature) and control system hardware and software. This presentation will focus on the control system design with specific attention on planned use of the National Instruments Compact RIO platform with the Experimental Physics and Industrial Control System (EPICS) software toolkit.
SLAC, Menlo Park, California, USA
Photonic crystal fibers (PCFs) represent a class of optical fibers which have a wide spectrum of applications in the telecom and sensing industries. Currently, the Advanced Accelerator Research Department at SLAC is developing photonic bandgap particle accelerators, which are photonic crystal structures with a central defect used to accelerate electrons and achieve high longitudinal electric fields. Extremely compact and less costly than the traditional accelerators, these structures can support higher accelerating gradients and will open a new era in high energy physics as well as other fields of science. Based on direct laser acceleration in dielectric materials, the so called photonic band gap accelerators will benefit from mature laser and semiconductor industries.
THALES, Colombes, France
BNL, Upton, Long Island, New York, USA
Two partial snakes overcome the vertical depolarizing resonances in the AGS. But a new type of depolarizing intrinsic resonance from horizontal motion appeared. We reduce these using horizontal tune jumps timed to these resonances. We gain a factor of five in crossing rate with a tune jump of 0.04 in 100 micro-sec. Two quadrapoles, we described in 2009 *, pulse 42 times, the current matching beam energy. The power supplies for these quads will be described in this conference**. The controls for the Jump Quad system is based on a BNL designed Quad Function Generator. Two modules are used; one for timing, and one to supply reference voltages. Synchronization is provided by a proprietary serial bus, the Event Link. The AgsTuneJump application predicts the times of the resonances during the AGS cycle and calculates the power supply trigger times from externally collected tune and energy verses time data and the Low and High PS voltage functions from a voltage to current model of the power supply. The system was commissioned during runs 09 & 10. Beam effects are described elsewhere in this conference***. Details of improvements, operation and the feed forward software will be described.
* JW Glenn, et al “AGS Fast Spin Resonance,-” PAC-09
** JL Mi, et al “AGS Tune Jump Power-” these proceedings
*** L.A.Ahrens, et al "Recent RHIC Motivated Polarized-" these proceedings
LBNL, Berkeley, California, USA
SINAP, Shanghai, People's Republic of China
ICST, Harbin, People's Republic of China
UMiss, University, Mississippi, USA
We describe the recent progress on the design and fabrication of the RFCC (RF and Coupling Coil) module for the international Muon Ionization Cooling Experiment (MICE). The MICE cooling channel has two RFCC modules; each has four 201-MHz normal conducting RF cavities and one superconducting solenoid magnet. The magnet is designed to be cooled by three cryocoolers. Fabrication of the RF cavities is complete; design and fabrication of the magnets are in progress. The first magnet is expected to be finished by the end of 2011.
CERN, Geneva, Switzerland
BNL, Upton, Long Island, New York, USA
JLAB, Newport News, Virginia, USA
All physics stores at the Relativistic Heavy Ion Collider are now established using simultaneous orbit, tune, coupling, and energy feedback during beam injection, acceleration to full beam energies, during the “beta-squeeze” for establishing small beam sizes at the interaction points, and during removal of separation bumps to establish collisions. In this report we describe the major changes made to enable these achievements. The proof-of-principle for additional chromaticity feedback will also be presented.
CERN, Geneva, Switzerland
ORNL, Oak Ridge, Tennessee, USA
Taking advantage of modern graphical editor software technology, a new Operator Interface (OPI) editor and runtime - Best OPI, Yet (BOY) - was developed by the Control System Studio (CSS) collaboration. It uses the Eclipse Graphical Editor Framework (GEF) to provide modern graphical editor functions, which makes it easy and intuitive to edit OPIs. Combined with Javascript and configurable rules, it is also easy to create powerful OPIs with complicated client-side logic. By simply providing the name of a Process Variable (PV), it will automatically handle the network connections. The graphical layer is decoupled from the data connection layer, conceptually allowing BOY to connect to arbitrary data sources, with current support including EPICS Channel Access and simulation PVs. BOY is integrated with the CSS platform, which provides inter-operability with other CSS tools. Fundamentally, it could also be integrated with other Eclipse Rich Client Platform (RCP) applications due to its plugin mechanism. We have several screens deployed at the Spallation Neutron Source (SNS), where BOY has proven to be stable in support of SNS operation.
ESS Bilbao, Bilbao, Spain
ESS-Bilbao, Zamudio, Spain
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
BNL, Upton, Long Island, New York, USA
The goal of the RHIC LLRF upgrade has been the development of a stand alone, generic, high performance, modular LLRF control platform, which can be configured to replace existing systems and to serve as a common platform for all new RF systems. The platform is also designed to integrate seamlessly into a distributed network based controls infrastructure, be easy to deploy, and to be useful in a variety of digital signal processing and data acquisition roles. Reuse of hardware, software and firmware has been emphasized to minimize development effort and maximize commonality of system components. System interconnection, synchronization and scaling is facilitated by a deterministic, high speed serial timing and data link, while standard intra and inter chassis communications utilize high speed, non-deterministic protocol based serial links. System hardware configuration is modular and flexible, based on a combination of a main carrier board which can host up to six custom or commercial daughter modules as required to implement desired functionality. This paper will provide an overview of the platform concept, architecture, features and benefits.
Fermilab, Batavia, USA
CERN, Geneva, Switzerland
ESS, Lund, Sweden
ORNL, Oak Ridge, Tennessee, USA
A non-destructive profile monitor has been installed and commissioned in the accumulator ring of the Spallation Neutron Source (SNS). The SNS Ring accumulates high intensity proton bunches of up to 1.5·1014 protons with a typical peak current of over 50 A and a bunch length of about 0.7 us during a 1 ms cycle. The profile monitor consists of two systems, one for each plane, with electron guns, correctors, defectors, and quadrupoles to produce pulsed electron beams that scan through the proton bunch. The proton bunch EM fields alter the trajectory of the electrons and their projection on a fluorescent screen. The projection is analyzed to determine the transverse profile of the proton bunch. The speaker will describe the theory, hardware, software, analysis, results, and improvements to these electron scanners. The results include a comparison to wire scanner profiles of extracted ring beam.
NSRRC, Hsinchu, Taiwan
Dimtel, San Jose, USA
LNLS, Campinas, Brazil
BNL, Upton, Long Island, New York, USA
SLAC, Menlo Park, California, USA
CERN, Geneva, Switzerland
LBNL, Berkeley, California, USA
The feedback control of intrabunch instabilities driven by E-Clouds or strong head-tail coupling (TMCI) requires sufficient bandwidth to sense the vertical position and drive multiple sections of a nanosecond scale bunch. These requirements impose challenges and limits in the design and implementation of the feedback system. This paper presents models for the feedback subsystems: receiver, processing channel, amplifier and kicker, that take into account their frequency response and limits. These models are included in multiparticle simulation codes (WARP/CMAD/Head-Tail) and reduced mathematical models of the bunch dynamics to evaluate the impact of subsystem limitations in the bunch stabilization and emittance improvement. With this realistic model of the hardware, it is possible to analyze and design the feedback system. This research is crucial to evaluate the performance boundary of the feedback control system due to cost and technological limitations. These models define the impact of spurious perturbations, noise and parameter variations or mismatching in the performance of the feedback system. The models are validated with simulation codes and measurements of lab prototypes.
LLNL, Livermore, California, USA
LBNL, Berkeley, California, USA
A one-dimensional Vlasov-Poisson model for sheet beams is presented to provide a simple framework for analysis of space-charge effects. Centroid and rms envelope equations including image charge effects are derived and reasonable parameter equivalences with commonly employed 2D transverse models of unbunched beams are established. This sheet beam model is applied to analyze several problems of fundamental interest. First, a sheet beam thermal equilibrium distribution in a continuous focusing channel is constructed and shown to have analogous properties to two- and three-dimensional thermal equilibrium models in terms of the equilibrium structure and Deybe screening properties. Second, the simpler formulation for sheet beams is exploited to explicitly calculate the distribution of particle oscillation frequencies within a thermal equilibrium beam. It is shown that as space-charge intensity increases, the frequency distribution becomes broad which suggesting robust stability properties for beams with strong space-charge.
Euclid TechLabs, LLC, Solon, Ohio, USA
LETI, Saint-Petersburg, Russia
ANL, Argonne, USA
Beam breakup (BBU) effects resulting from parasitic wakefields limit considerably the intensity of the drive beam that can be transported through a dielectric accelerating structure and hence the accelerating field that can be achieved. We have been developing techniques to control BBU effects using a quadrupole channel or solenoid surrounding the wakefield device. We report here on the status of simulations and experiments on BBU and its mitigation, emphasizing an experiment at the Argonne Wakefield Accelerator facility using a 26 GHz dielectric wakefield device fitted with a solenoid to control BBU. We present calculations based on a particle-Green’s function beam dynamics code (BBU-3000) that we are developing. The code allows rapid, efficient simulation of BBU effects in advanced linear accelerators.
LBNL, Berkeley, California, USA
Beam-beam effects limit luminosity in high energy colliders. Parallel beam-beam simulation codes were developed to study those beam-beam effects and to help the collider design. In this paper, we will present a parallel optimization algorithm integrating together with the parallel beam-beam simulation to optimize the luminosity of the colliding beams. This algorithm is based on a differential evolutionary global optimization method and takes advantage of the two-level parallelization in both parallel search and parallel objective function evaluation. This significantly increases the scalability of the simulation on peta-scale supercomputers and reduces the time for finding the optimal working point.
LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
CERN, Geneva, Switzerland
Transverse Single-Bunch Instabilities due to Electron Cloud effect are limiting the operation at high current of the SPS at CERN. Recently a high-bandwidth Feedback System has been proposed as a possible solution to stabilize the beam and is currently under study. We analyze the dynamics of the bunch actively damped with a simple model of the Feedback in the macro-particle code WARP, in order to investigate the limitations of the System such as the minimum amount of power required to maintain stability. We discuss the feedback model, report on simulation results and present our plans for further development of the numerical model.
SLAC, Menlo Park, California, USA
CERN, Geneva, Switzerland
LBNL, Berkeley, California, USA
We present analysis of beam motion data obtained in high intensity SPS MD studies in 2009 and 2010. The single-bunch vertical E-cloud motion seen in parts of the bunch train after injection shows large tune shifts (roughly 0.02 above the 0.185 tune) developing between tail and head of unstable bunches. The unstable vertical motion has spectral content up to roughly 1.2 GHz and a quasi-periodic growth and decoherence relaxation oscillation effect is seen with time scales of hundred turns. Beam slice FFT and RMS techniques are illustrated to extract parameters important for the design of wide-band vertical feedback system, such as a growth rates of unstable motion, tune shifts within a single bunch and characterization of the bandwidth of the unstable structures within a bunch. We highlight the impact of synchrotron motion and injection transients on a proposed vertical processing channel. We present our MD plans including the beam driving process, developments in reduced model / identification techniques to extract dynamics from experimental and simulation data.
*J. Fox et al., ‘‘SPS Ecloud Instabilities - Analysis Of Machine Studies And Implications For Ecloud Feedback,'' IPAC'10, WEPEB052
Fermilab, Batavia, USA
Fermilab Main Injector has been operating at high Beam Power Levels since 2008 when multi-batch slip stacking became operational. In order to increase the beam power even further we have to address the localized beam loss due to beam left over in the Injection Kicker Gap during slip stacking. A set of Gap Clearing Kickers that kick any beam left in the injection gap to the beam abort have been installed during the summer of 2009 and became operational in October 2010. The kicker performance and its effect on beam losses will be described.
CEA, Pontfaverger-Moronvilliers, France
TU Darmstadt, Darmstadt, Germany
The S-DALINAC is a superconducting recirculating electron accelerator with a final energy of 130 MeV. It operates in cw at 3 GHz. It accelerates beams of either unpolarized or polarized electrons and is used as a source for nuclear- and astrophysical experiments at the university of Darmstadt since 1987. We will report on the operational findings, recent modifications and on the future upgrade plans: First results from the new digital rf control system, the injector current upgrade and the improved longitudinal working point will be presented. In addition, an overview of the future plans, namely installing an additional recirculation path and two scraper systems will be given.
ORNL, Oak Ridge, Tennessee, USA
ORNL RAD, Oak Ridge, Tennessee, USA
LANL, Los Alamos, New Mexico, USA
JLAB, Newport News, Virginia, USA
Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed.
Fermilab, Batavia, USA
INFN-Pisa, Pisa, Italy
An adaptive Least Squares algorithm to control Lorentz force detuning in SRF cavities has been developed and tested in the HTS at FNAL. During open-loop tests in the FNAL HTS, the algorithm was able to reduce LFD in a 9-cell 1.3 GHz elliptical cavity operating at 35 MV/m from 600 Hz to less than 10 Hz during both the fill and the flattop. The algorithm was also able to adapt to changes in the gradient of the cavity and to changes in the pulse length.
BNL, Upton, Long Island, New York, USA
We are presenting the layout and the optics of a beam line to be used as a medical gantry in radiation therapy. The optical properties of the gantry’s beam line are such as to make the beam line achromatic and uncoupled. These two properties make the beam spot size, which is delivered and focused by the gantry, on the tumor of the patient, independent of the angular orientation of the gantry. In this paper we present the layout of the magnetic elements of the gantry, and also present the theoretical basis for the optics design of such a gantry.
* N. Tsoupas et. al. “Uncoupled achromatic tilted S-bend” Presented at the 11th Biennial European Particle Accelerator Conference, Genoa, Italy, June 23-27,2008
RadiaBeam, Santa Monica, USA
BNL, Upton, Long Island, New York, USA
There are 60 12×150A current leads distributed in 6 RHIC service buildings; each current lead delivers power supply current from room temperature to cryogenic temperature in RHIC. Due to the humid environment, condensation frequently occurs and ice was quickly formed during operation, especially during an extensive storage period. This condition generated warnings and alarms that personal had to respond to, in order to provide temporary solutions, to keep the machine operational. A temperature control system was designed to avoid such occasions. We will discuss design, implementation and some results of this design in this paper.
ANL, Argonne, USA
An efficient means was developed to manage multi-author documents using software components not usually run together that are both freely available and free of cost: Concurrent Version Software (CVS), LaTeX typesetting software, and the Unix make utility. Together they solve the main problem with multi-author documents: losing track of "latest" version, tracking author contributions, and a strict enforcement of document format. APS has used this system for two large documents with about a dozen authors each: a 2007 white paper (150 pages) on a ERL proposal and a chapter (200 pages) of the APS Upgrade CDR. We stress the use of LaTeX because the plain-text format is amenable to version comparisons and the macro-based system allows last-minute global format changes. Several contributions from APS to this conference actually use this system.
JLAB, Newport News, Virginia, USA
We describe the design of the SRF ERL providing the CW electron drive beam at the Jefferson Lab UV FEL. Based on the same 135 MeV linear accelerator as – and sharing portions of the recirculator with – the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a novel bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation (including correction of RF curvature effects) without the use of magnetic chicanes or harmonic RF. Stringent phase space requirements at the wiggler, low beam energy, high beam current, and use of a pre-existing facility and legacy hardware subject the design to numerous constraints. These are imposed not only by the need for both transverse and longitudinal phase space management, but also by the potential impact of collective phenomena (space charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation (CSR)), and by interactions between the FEL and the accelerator RF system. This report addresses these issues and presents the accelerator design solution that now successfully supports FEL lasing.
SLAC, Menlo Park, California, USA
SPEAR3 beam is now delivered to users in a "frequent fill" mode in which beam is injected into the storage ring, with beam-line shutters open, on a periodic schedule so that the beam current is kept constant to within 1% of its average value. This goal was achieved with the constraints of having the SPEAR3 injector run at very high reliability and ensuring that there would be no challenges to the beam containment system in this operational mode. This paper presents the accelerator development, the hardware changes, and the software developed to implement this operational mode.
LBNL, Berkeley, California, USA
LLNL, Livermore, California, USA
The electron photo-gun of the Advanced Photo-injector EXperiment project (APEX) at the LBNL will be driven by a compact fiber laser for different photo-cathode experiments during the initial phase of the project. The fiber laser, developed at the Lawrence Livermore National Laboratory, is designed to deliver μJ/pulse at 1064 nm system that is frequency doubled to deliver light at 532nm with 1MHz repetition rate and 1ps pulse length optimized for photo-emission with multi-alkali antimonide cathodes. For Cs2Te and diamond amplifier cathodes, the 4th harmonic will be generated by doubling frequency again in a non-linear crystal. Due to the requirement of small emittance for the electron beam, the laser pulse will be shaped in space and time for 532nm and UV lights, in general with a constant intensity in cross section with a sharp radial cutoff, and elliptical or rectangular distribution in the longitudinal plane. Diagnostics of the laser beam itself and of the cathode will be integrated with techniques such as cross- correlation, streak camera, and virtual cathode imaging, not only to monitor the laser pulse but also to provide automated feedbacks.
JLAB, Newport News, Virginia, USA