| Paper | Title | Page |
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| WE6RFP008 | Design of a 1.3 GHZ Single 9 Cell SC Cavity Test Cryomodule for ILC Collaboration at IHEP | 2796 |
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Funding: Work supported by NSFC 10525525 In order to obtain the design, manufacture and operational experiences on the SRF cryomodule toward ILC, a test cryomodule for 1.3GHz single 9-cell SC cavity was designed by IHEP (Institute of High Energy Physics) and TIPC (Technical Institute of Physics and Chemistry) jointly. This cryomodule will be used as a 1.3GHz 9 cell SC cavity horizontal test facility. The cryogenic system for the cryomodule is designed and will be operated at 2.0K, with the saturated superfluid helium. The major requirements, design, simulation results of the cryomodule are reported in the paper. This key component of a superconducting accelerator test unit will be built in the near future at IHEP. |
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| TU5PFP074 | Recent Results of the Vertical Test for 1.3GHz Superconducting 9-Cell Cavities at KEK-STF | 996 |
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A new vertical test facility for L-band multi-cell cavities has been completed in support of development efforts of ILC (International Linear Collider) and ERL (Energy Recovery Linac) projects at STF (Superconducting rf Test Facility) of KEK. The facility possesses a clean booth for pre-tuning the cavities, four cavity stands to prepare the cavities prior to vertical testing, a half-underground pit which accommodates up to two vertical cryostats which can be pumped and operated separately under a movable iron shield. Vertical testing of the cavities, with a 400 W high-power amplifier and with a temperature-mapping (T-mapping) and additional monitoring systems, is supervised from a control room which overlooks the entire facility. This paper describes the specific details of the facility and results from its initial pilot operation that was conducted in Summer-Fall of 2008. |
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| TU5PFP076 | A New Cavity Diagnostic System for the Vertical Test of 1.3GHz Superconducting 9-Cell Cavities at KEK-STF | 1002 |
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A new cavity diagnostic system has been introduced for vertical testing of nine-cell L-band superconducting cavities at KEK-STF. The present system is based on approximately 300 carbon resistors for temperature-mapping (T-mapping), and approximately 40 PIN photo diodes for detecting emission of X-rays. The system can accommodate up to total 600 sensors in needed in the future. While most of the sensors are attached to the cavity exterior in a pre-determined regular pattern, some sensors can be strategically placed at non-regular positions so as to watch the areas which are considered “suspicious” as per the surface inspection done prior to vertical testing. Data from the sensors can be collected every 100 msec. The data can be graphically displayed online and are stored for offline analysis. This paper describes the details of this system, together with results from its initial pilot operation which was done with a nine-cell cavity on loan from FNAL (AES#001). Effectiveness of the combined use of T-mapping and PIN photo diodes in operation of the pi-mode and other pass-band modes in conjunction with surface inspection is discussed. |
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| TU5PFP038 | ILC 1.3 GHz Superconducting RF Technology Development Program at IHEP | 906 |
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Funding: NSFC 10525525 With the aim to develop 1.3 GHz superconducting radio-frequency (SCRF） technology in the frame of ILC collaboration, IHEP has started a program to build a SCRF Accelerating Unit. This unit contains a 9-cell 1.3 GHz superconducting cavity, a short cryomodule, a high power input coupler, a tuner, a low level RF system and a high power RF source, etc. This program also includes the SCRF laboratory upgrade, which will permit the unit to be built and tested at IHEP. We will use this unit as a horizontal test stand for many 9-cell cavities and other components (e.g. input couplers, tuners), as in Europe and North America. In this paper, we report the recent R&D status and the future plan of this program. |
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| TU5PFP075 | Observation and Numerical Calculation of Lorentz-Detuning for the Cryomodule Test of STF Baseline Cavities at KEK-STF | 999 |
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A pulsed RF operation of four units of 9-cell L-band (1.3 GHz) cavities in a horizontal cryostat (cryo-module) was conducted in 2008 as part of R&D efforts at STF at KEK for ILC. A series of compensation experiments were conducted for Lorentz-detuning effects, which are critically important for pulsed RF operation of high-gradient linacs based on superconducting cavity technologies. The experiments were done at a repetition rate of 5 Hz with RF pulses of a width of 1.5 msec, and the typical accelerating gradient within the cavities was 20 32 MV/m. Two types of compensation techniques have been tested. In a “feed-forward” method, piezo actuators on individual cavity tuners are activated to mechanically control the tuning of the cavity in synchronization with the RF pulses. In a “feed-back” method, the low-level RF system is driven so as to maintain the average of “I” and “Q” components of the cavities as constant. This paper reports the experimental results using the various parameters of the piezo control to compensate the effect of Lorentz-detuning. These results are consistent with the numerical calculation postulating that two mechanical modes mainly contribute to the effect. |