TU Darmstadt, Darmstadt
USTC/NSRL, Hefei, Anhui
NSCL, East Lansing, Michigan
TRIUMF, Vancouver
WUT, Warsaw
DESY, Hamburg
TJNAF, Newport News, Virginia
DESY, Hamburg
ORNL, Oak Ridge
*Spallation Neutron Source, ORNL and LANL
| Paper | Title | Page |
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| TUP46 | A New Control System for the S-DALINAC | 372 |
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| We will present recent results of the development of a new control system for the superconducting cw electron accelerator S-DALINAC. This system will be based on common industrial standards. Due to the large number of special devices existing to control the beamline, a simple and cheap communication interface is required to replace the current proprietary bus topology. The existing devices will be upgraded by a microcontroller based CAN bus interface as communication path to a control server. The servers themselves may be distributed over the location, giving required applications access to the device parameters through a TCP/IP connection. As application layer protocol for the Client Server communication a special binary protocol and a text protocol based on XML are considered. | ||
| TUP75 | The High Accuracy RF Phase Detector Research for 200 MeV LINAC | 444 |
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| The basic configuration of one experimental RF Phase detector and its research significance is introduced by characteristic of Hefei 200 MeV RF Linear accelerator and developments of RF Phase detector technology. The beam energy could be stabilized by implementing RF Phase detector into phase locked system for 5 cascaded accelerator tubes, which composed 200 MeV linac as the injector of Hefei Light Source (HLS). The tabletop experiments are given and the RF Phase detector is tuned in the off-line status. The microwave in 2856 MHz under CW mode is differentiated accurately by the developed RF phase detector. The measured results are better than prediction. The accuracy of the basic configuration of the RF Phase detector is verified, which establishes foundations for further in-line experiments. | ||
| TUP76 | Adaptive Feedforward Cancellation of Sinusoidal Disturbances in Superconducting RF Cavities | 447 |
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| A control method, known as adaptive feedforward cancellation (AFC) is applied to damp sinusoidal disturbances due to microphonics in superconducting RF (SRF) cavities. AFC provides a method for damping internal, and external sinusoidal disturbances with known frequencies. It is preferred over other schemes because it uses rudimentary information about the frequency response at the disturbance frequencies, without the necessity of knowing an analytic model (transfer function) of the system. It estimates the magnitude and phase of the sinusoidal disturbance inputs and generates a control signal to cancel their effect. AFC, along with a frequency estimation process, is shown to be very successful in the cancellation of sinusoidal signals from different sources. The results of this research may significantly reduce the power requirements and increase the stability for lightly loaded continuous-wave SRF systems. | ||
| TUP77 | Status of RF Control System for ISAC II Superconducting Cavities | 450 |
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| The rf control system for ISAC II superconducting cavities is a hybrid analogue/digital system using self-excited feedback loop. It has undergone more than a year of testing and improvements have been made to every aspect of the system, including power up sequencing, phase detection, loop regulation, data acquisition as well as communication with EPICS. With a loaded Q of 100,000, amplitude regulation bandwidth of 20 Hz, phase regulation bandwidth of 5 Hz have been achieved. | ||
| TUP78 | Diagnostics for the Low Level RF Control for the European XFEL | 453 |
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| One of the most important aims of the diagnostic system is to provide high reliability. This article describes the concept and the proposal for diagnostic system for Low Level Radio Frequency system for EU-XFEL. It enables immediate location of faults and understanding of their causes, tests the functionality of LLRF system, tests each the electronic board and connections. Diagnostic system tests different system components and compares results from these tests with e.g. from power supplies monitors. Hardware, software and database aspect of diagnostic system is presented. The main part of this paper is devoted to hardware and software specification. | ||
| TUP79 | A New RF System for the CEBAF Normal Conducting Cavities | 456 |
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| The CEBAF Accelerator at Jefferson Lab is a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. CEBAF also has numerous normal conducting cavities for beam conditioning in the injector and for RF extraction to the experimental halls. The RF systems that presently control these cavities are becoming expensive to maintain, therefore a replacement RF control system is now being developed. For the new RF system, cavity field control is maintained digitally using an FPGA which contains the feedback algorithm. The system incorporates digital down conversion, using quadrature under-sampling at an IF frequency of 70 MHz. The VXI bus-crate was chosen as the operating platform because of its excellent RFI/EMI properties and its compatibility with the EPICS control system. The normal conducting cavities operate at both the 1497 MHz accelerating frequency and the sub-harmonic frequency of 499 MHz. To accommodate this, the new design will use different receiver-transmitter daughter cards for each frequency. This paper discuses the development of the new RF system and reports on initial results. | ||
| WE103 | State of the Art in RF Control | 523 |
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| Nowadays the designer of a new rf control system has access to a wealth of powerful digital, analog, and rf circuitry. The requirements for the rf control system have changed from only controlling the amplitude and phase of the accelerating field to the required degree to stability. Additional tasks include exception handling and extensive build-in diagnostics while pursuing issues related to reliability, operability, and maintainability. Also operation close to the performance limit must be supported while maximizing the availability of the accelerator. With many accelerator projects in planning or under construction several state-of-the art rf control designs have evolved. This paper will present an overview of this new technology and discuss its performance. | ||
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Transparencies | |
| FR201 | Accelerator Control and Global Networks - State of the Art | 847 |
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As accelerators increase in size and complexity, demands upon their control systems increase correspondingly. Machine complexity is reflected in complexity of control system hardware and software and careful configuration management is essential. Model-based procedures and fast feedback based upon even faster beam instrumentation are often required. Managing machine protection systems with tens of thousands of inputs is another significant challenge. Increased use of commodity hardware and software introduces new issues of security and control. Large new facilities will increasingly be built by national (e.g. SNS) or international (e.g. a linear collider) collaborations. Building an integrated control system for an accelerator whose development is geographically widespread presents particular problems, not all of them technical. Recent discussions of a “Global Accelerator Network” include the possibility of multiple remote control rooms and no more night shifts. Based upon current experience, observable trends and rampant speculation, this paper looks at the issues and solutions-–-some real, some probable, and some pie-in-the-sky.
*Spallation Neutron Source, ORNL and LANL |
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