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Other Keywords |
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| MOPAS082 |
Status of the Spallation Neutron Source Superconducting RF Facilities
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vacuum, cryogenics, controls, radiation |
623 |
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- D. Stout
- S. Assadi, I. E. Campisi, F. Casagrande, M. T. Crofford, W. R. DeVan, X. Geng, T. W. Hardek, S. Henderson, M. P. Howell, Y. W. Kang, W. C. Stone, W. H. Strong, D. C. Williams, P. A. Wright
ORNL, Oak Ridge, Tennessee
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Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy
The SNS project was completed with only limited SRF facilities installed as part of the project, namely a 5 MW, 805 MHz RF test stand, a fundamental power coupler processing system, a concrete test cave shell, and temporary cleaning/assembly facilities. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade R&D. Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly/disassembly and cavity processing also is being designed. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.
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| MOPAS086 |
FPGA Based ILC Cavity Simulator
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simulation, controls, resonance, linear-collider |
632 |
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- A. Grassellino
- J. K. Keung, F. M. Newcomer
University of Pennsylvania, Philadelphia, Pennsylvania
- N. Lockyer
TRIUMF, Vancouver
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In the proposed International Linear Collider (ILC) design, the Low Level RF (LLRF) control system plays the important role of maintaining the proper phase and amplitude information for the RF field inside the superconducting cavities. The high operational overhead of the high power cryogenic hardware and the risk of its damage during the control hardware tests make it necessary to have a LLRF test bed independent of the real hardware. Thus, we have developed a Real Time Simulator (RTS), an FPGA based ILC RF unit simulator, which will be useful for the testing and commissioning of the Low Level RF control system, including the exception handling capabilities, and possibly as a noiseless behavioral reference for each cryomodule during operation. The RTS has been implemented on a Lyrtech VHS-ADAC board. It includes effects such as Lorentz Detuning and presently an overall latency lower than 200 nanoseconds has been achieved. The status of the RTS and the conclusions derived from the simulations will be reported, along with LLRF interface tests results.
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| WEXAB01 |
ILC Reference Design and Challenges
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linear-collider, collider |
1944 |
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- T. O. Raubenheimer
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The International Linear Collider (ILC) is a 500 GeV center-of-mass electron-positron linear collider based on 1.3 GHz superconducting rf. For the past two years, the ILC design has been developed by an international collaboration, the Global Design Effort. A draft Reference Design Report (RDR) for the ILC was released in February 2007 and, after international review, the final draft will be published in mid-July, 2007. This talk will describe the ILC design along with the outstanding R&D and engineering challenges. The next step is to complete an Engineering Design (EDR) by 2010, and plans for this phase will also be discussed.
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| WEYAB01 |
Overview of Industrialization Strategies for ILC
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linear-collider, linac, collider, electron |
1961 |
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- D. Proch
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ILC is by far the largest and most challenging application of superconducting RF accelerator technology. Starting from the experience with TESLA and XFEL I will describe the level of industrial competence in the three global regions (Asia, America and Europe). In particular I will refer to the state of the art of cavity fabrication, module assembly and auxiliary components as well as to the synergy with the XFEL project. I will use the fabrication experience with SC magnets for LHC at CERN as benchmark for industrialization strategies for ILC.
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| WEPMN002 |
Tuner Control in TRIUMF ISAC 2 Superconducting RF System
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feedback, controls, linac, coupling |
2047 |
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- K. Fong
- M. P. Laverty, Q. Zheng
TRIUMF, Vancouver
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The TRIUMF ISAC 2 superconducting RF system operates on self-excited, phase locking mode. A mechanical tuner is used to minimize the required RF power. The tuner derives the tuning information from the phase shift around the self-excited loop. Its accuracy is however reduced by phase drift in the amplifier due to thermal effects. Cross correlation between the In-phase and the Quadrature-phase errors is used to detect this drift. A Kalman filter is used to combine these information to control the movement of the tuner.
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| WEPMN047 |
Electro-polished Cavities Using China Ningxia Large Grain Niobium Material
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vacuum, linear-collider, collider, electron |
2143 |
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- Z. G. Zong
- F. Furuta, H. Inoue, T. Saeki, K. Saito
KEK, Ibaraki
- J. Gao, M. Q. Ge, Q. J. Xu, J. Y. Zhai
IHEP Beijing, Beijing
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For the International Linear Collider (ILC), superconducting RF cavity technology was chosen. The superconducting cavity is made of polycrystalline niobium material so far. However, the material cost is high and the cavity performance has a rather scatter now. Large grain niobium (LG) cavity is an excellent idea because it simplifies the production process and results in less expensive. JLAB and DESY are pushing the R&D in last two years. KEK also has started to investigate LG. Three cavities with Ichiro shape were made of Chinese large grain niobium (Ningxia). A series of vertical tests has been carried out on several different surfaces treatment procedures by electropolishing. One cavity has reached the high gradient of more than 43 MV/m repeatedly. Other two cavities are still under testing. In this paper, the features of LG on electropolishing will be described with Ningxia large grain niobium material.
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| WEPMN062 |
HOM Analysis and Design of its Removal System for SRF 3rd Harmonic RF Cavity in PLS
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electron, storage-ring, impedance, vacuum |
2179 |
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- Y. U. Sohn
- J. Choi, M.-H. Chun, J. Y. Huang, I. S. Ko, I. S. Park
PAL, Pohang, Kyungbuk
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Funding: Korea Ministry of Science & Technology
Pohang Accelerator Laboratory has prepared to SRF 3rd harmonic cavity to increase beam lifetime and to damp orbit instability by lengthening electron bunch in PLS. The SRF cavity was developed and its vertical test was done already with success. Higher order modes were analyzed to optimize its performance in beam orbit. Most of them are not effective to electron beam, while the others have possibility to impact orbit stability. These harmful HOMs can be removed by HOM absorber installed in beam pipe. This paper reports the HOM analysis and design of its removal system.
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| WEPMN094 |
Experience with Capture Cavity II
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resonance, vacuum, electron, controls |
2251 |
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| WEPMN096 |
Status of the 3.9-GHz Superconducting RF Cavity Technology at Fermilab
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controls, monitoring, vacuum, cryogenics |
2254 |
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- E. R. Harms
- T. T. Arkan, L. Bellantoni, H. Carter, H. Edwards, M. Foley, T. N. Khabiboulline, D. V. Mitchell, D. R. Olis, A. M. Rowe, N. Solyak
Fermilab, Batavia, Illinois
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Funding: This work supported by Universities Research Association Inc. under contract DE-AC02-76CH00300 with the U. S. DOE.
Fermilab is involved in an effort to assemble 3.9 GHz superconducting RF cavities into a four cavity cryomodule for use at the DESY TTF/FLASH facility as a third harmonic structure. The design gradient of these cavities is 14 MV/m limited by thermal heat transfer. This effort involves design, fabrication, intermediate testing, assembly, and eventual delivery of the cryomodule. We report on all facets of this enterprise from design through future plans. Included will be test results of single 9-cell cavities, lessons learned, and current status.
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| WEPMN103 |
Mechanical Stability Study of Capture Cavity II at Fermilab
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vacuum, resonance, cryogenics, monitoring |
2274 |
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- M. McGee
- Y. M. Pischalnikov
Fermilab, Batavia, Illinois
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Problematic resonant conditions at both 18 Hz and 180 Hz were encountered and identified early during the commissioning of Capture Cavity II (CC2) at Fermilab. CC2 consists of an external vacuum vessel and a superconducting high gradient (close to 25 MV/m) 9-cell 1.3 GHz niobium cavity, transported from DESY for use in the A0 Photoinjector at Fermilab. An ANSYS modal finite element analysis (FEA) was performed in order to isolate the source of the resonance and directed the effort towards stabilization. A novel idea was implemented, by using a fast piezoelectric tuner to excite (or shake) the cavity at different frequencies (from 10 Hz to 200 Hz) as a low-range sweep for analysis purposes. Both warm (300 K) and cold (1.8 K) accelerometer measurements at the cavity were taken as the resonant 'fix' was applied. FEA results, cultural and technical noise investigation, and stabilization techniques are discussed.
Operated by Universities Research Association, Inc., under Contract No. DE-AC02-76CH03000 with the U. S. Department of Energy#mcgee@fnal.gov
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| WEPMN105 |
Fast Thermometry for Superconducting RF Cavity Testing
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kaon, radio-frequency, higher-order-mode, instrumentation |
2280 |
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- D. F. Orris
- L. Bellantoni, R. H. Carcagno, H. Edwards, E. R. Harms, T. N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, Y. M. Pischalnikov
Fermilab, Batavia, Illinois
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Funding: Work supported by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.
Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several RTDs were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of this fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.
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| WEPMS007 |
Manufacture and Performance of Superconducting RF Cavities for Cornell ERL Injector
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emittance, electron, acceleration, gun |
2340 |
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- R. L. Geng
- P. Barnes, B. Clasby, J. Kaminski, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, J. Sears, V. D. Shemelin, N. Sherwood, M. Tigner
CLASSE, Ithaca
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Funding: Work supported by NSF
Six 1300 MHz superconducting niobium 2-cell cavities are manufactured for the prototype of Cornell ERL injector to boost the energy of a high current, low emittance beam produced by a DC gun. Designed for high current beam acceleration, these cavities have new characteristics as compared to previously developed low-current cavities such as those for TTF. Precision manufacture is emphasized for a better straightness of the cavity axis so as to avoid unwanted emittance dilution. We present the manufacturing, processing and vertical test performance of these cavities. We also present the impact of new cavity characteristics to the cavity performance as learnt from vertical tests. Solutions for improving cavity performance are discussed.
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| WEPMS044 |
High Power Switch for the SMTF Modulator
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controls, klystron, monitoring, power-supply |
2445 |
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- M. N. Nguyen
- R. L. Cassel
SLAC, Menlo Park, California
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Funding: Work supported by the Department of Energy under contract No. DE-AC03-76SF00515.
A compact, water cooled, high power switch for the Superconducting Module Test Facility (SMTF) long-pulse klystron modulator has been designed and implemented at the Fermi National Accelerator Laboratory (FNAL). This solid-state switch is composed of six series devices, each having a rating of 4.5 kV at 2000 Adc. Latest generation, press-pack IGBT modules are utilized to reduce the physical size and complexity of the switch assembly. The new switch and its associated controller provide a high degree of redundancy and fail-safe operation, which meets the modulator requirements. This paper describes the general switch assembly, IGBT protection and control schemes, and test results.
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| WEPMS055 |
SQUID-based Nondestructive Testing Instrument of Dished Niobium Sheets for SRF Cavities
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pick-up, controls, superconductivity, micro-particles |
2469 |
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- Q. S. Shu
- I. Ben-Zvi
BNL, Upton, Long Island, New York
- G. Cheng, I. M. Phipps, J. T. Susta
AMAC, Newport News, Virginia
- P. Kneisel, G. Myneni
Jefferson Lab, Newport News, Virginia
- J. Mast, R. Selim
CNU, Newport News
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Funding: Acknowledgment: This work is supported by DOE grant DE-FG02-05ER84241
Currently available technology can only inspect flat sheets and allow the elimination of defective flat sheets before the expensive forming and machining of the SRF cavity half-cells, but it does not eliminate the problem of remaining or uncovered surface impurities after partial chemical etching of the half-cells, nor does it detect any defects that may have been added during the fabrication of the half-cells. AMAC has developed a SQUID scanning system based on eddy current technique that allows the scanning of curved Nb samples that are welded to make superconducting RF cavity half-cells. AMAC SQUID scanning system successfully located the defects (Ta macro particles about 100 mm diameter) in a flat Nb sample (top side) and was able to also locate the defects in a cylindrical surface sample (top side). It is more significant that the system successfully located the defects on the backside of the flat sample and curved sample or 3-mm from the top surface. The 3-D SQUID-based Nondestructive instrument will be further optimized and improved in making SRF cavities and allow inspection and detection during cavity manufacturing for achieving highest accelarating fields.
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| WEPMS082 |
PVC - An ILC RF Cryomodule Software Simulator
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feedback, controls, klystron, simulation |
2523 |
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- J. K. Keung
- N. Lockyer
TRIUMF, Vancouver
- S. Nagaitsev
Fermilab, Batavia, Illinois
- F. M. Newcomer
University of Pennsylvania, Philadelphia, Pennsylvania
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The Penn Virtual Cavity (PVC) simulator is a object oriented RF Cavity simulator with a user friendly Linux GUI, as well as a web interface. It is a tool to help understand the effects of each component in the RF system. It can simulate an International Linear Collider (ILC) cryomodule consisting of eight 9-cell cavities, together with its associated high voltage modulator, a klystron, and RF power distribution system. The uses range from experts designing LLRF control algorithms, to beginners learning about the general RF characteristics of the SRF cavities. PVC explores effects such as Lorentz Detuning, beam loading (with bunch to bunch fluctuations), 8/9pi modes, I/Q feedback and feedforward, cavity Q-drop, amplitude and phase jitter and ripples, as well as calibration errors. The current status of the PVC and the conclusions derived from the simulations will be reported, along with comparisons to the DESY-TTF cryomodules.
http://einstein.hep.upenn.edu/~keungj/simulation.html
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| THIAKI03 |
Design and Fabrication of Superconducting Cavities for STF
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electron, factory, vacuum |
2674 |
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| THIAKI05 |
European Industries Potential Capabilities on Superconducting RF Accelerator Modules
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linac, synchrotron, vacuum, RF-structure |
2680 |
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- H. Vogel
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European Industry has been supporting accelerator projects in the past and will be supporting future projects. Larger numbers of superconducting accelerator modules with guaranteed performance parameters have been supplied for example for LEP at CERN and superconducting cavities have been supplied also with guarantees for CEBAF at Jefferson Lab, the proton linear accelerator for the Spallation Neutron Source, Oak Ridge, and for the rf system for LHC. A significant number of cavities have been supplied in support of the TTF/ILC activities. With a view to the future European X-FEL linear accelerator it is expected that turn-key accelerator modules will be requested from industry. A review of the European Industries supplies in the past and present will be given to show their capabilities for the future ILC.
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Slides
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| THIBKI04 |
Developments of Long-pulse Klystron Modulator for KEK Super-conducting RF Test Facility
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klystron, controls, simulation, power-supply |
2691 |
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- H. Mori
- M. Akemoto, S. Fukuda, H. Honma, H. Nakajima, T. Shidara
KEK, Ibaraki
- K. Furuya
Nichicon (Kusatsu) Corporation, Shiga
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NICHICON (KUSATSU) CORPORATION and KEK have developed a novel long-pulse klystron modulator for both of single-beam tube(136kVp*100A) and multi-beam tube(120kVp*140A). The main features are; - crowberless system with optimized IGBT snubber circuit, - compact and highly reliable Self-Healing capacitors, - HV & LV twin pulse transformers of laminated steel core for reduced tank volume. Detailed configuration and test results to be presented.
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Slides
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| THICKI04 |
Development of STF Cryogenic System in KEK
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cryogenics, controls, booster, vacuum |
2701 |
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- J. Yoshida
- K. Hara, K. Hosoyama, Y. Kojima, H. Nakai, K. Nakanishi
KEK, Ibaraki
- T. Ichitani, S. Kaneda
Taiyo Nippon Sanso Corporation, Kawasaki-city Kanagawa Pref.
- T. Kanekiyo
Hitachi Technologies and Services Co., Ltd., Kandatsu, Tsuchiura
- M. Noguchi
Mayekawa MFG. Co., Ltd., Moriya
- S. Sakuma, K. Suzuki
Taiyo Nippon Sanso Higashikanto Corporation, Hitachi-shi, Ibaraki-Perf.
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Under the leadership of KEK, the collaborating design activity has been performed in KEK in order to develop the STF (Superconducting RF Test Facility) cryogenic system, together with some positive Japanese industrial members. As the first activity of the collaboration, the initial plant of STF cryogenic system with capacity of 30W at 2.0K has been constructed for the testing of STF cryomodule, and been ready for its operation in KEK. In this session, the present status and schedule of STF cryogenic system in KEK shall be briefly reported.
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Slides
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