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ABSTRACT: Cornell is building a 1.3 GHz Injector Cryomodule for an ERL prototype. The cryomodule consists of five two-cell niobium cavities, each cavity having two coaxial input couplers. Cavity and coupler pairs require acceptance testing at high power prior to assembly in the injector cryomodule. A liquid nitrogen cryostat for testing the couplers at high power has been built and the first input coupler test is complete. In addition, a Horizontal Test Cryostat (HTC) is being built to test input coupler pairs and cavities as a set. The first HTC test is scheduled for summer 2007. Details for instrumentation of the Coupler Test Cryostat (CTC) and HTC are presented.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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ABSTRACT: The first two RF power couplers for the ERL injector, currently under construction at Cornell University, have been fabricated. The couplers were assembled in the liquid nitrogen cryostat, built for their tests. A 15 kW CW IOT transmitter was available for coupler tests. A resonant ring was used for an additional increase of power. The couplers were successfully tested up to the goal power level of 50 kW CW. However, the first pair of couplers showed an excessive temperature rise at some points. Therefore, minor changes in the design have been done to improve cooling.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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ABSTRACT: Cornell University is developing and fabricating a SRF injector cryomodule for the acceleration of the high current (100 iriA) beam in the Cornell ERL prototype and ERL light source. Major challenges include emittance preservation of the low energy, ultra low emittance beam, cw cavity operation, and strong HOM damping with efficient HOM power extraction. Prototypes have been completed for the 2-cell niobium cavity with helium vessel, coaxial blade tuner with piezo fine tuners, twin high power input couplers, and beam line HOM absorbers loaded with fer- rites and ceramics. Axial symmetry of HOM absorbers, together with two symmetrically placed input couplers per cavity, avoids transverse on-axis fields, which would cause emittance growth. A one-cavity cryostat has been designed following concepts of the TTF cryostat, and is presently under fabrication and assembly. The cryostat design has been optimized for precise cavity alignment, good magnetic shielding, and high dynamic cryogenic loads from the RF cavities, input couplers, and HOM loads. In this paper we report on the status of the assembly and first test of the one-cavity test cryostat.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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S. Belomestnykh,
R. Kaplan,
H. Padamsee, P. Quigley,
J. Reilly,
J. Sears,
V. Veshcherevich,
S. Bauer,
M. Pekeler,
H. Vogel, [......],
E. Matias,
J. Stampe,
Ch. Wang,
L.H. Chang,
M.C. Lin,
T.T. Yang,
M.S. Yeh,
F.Z. Hsiao,
G.H. Luo,
C.T. Chen
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ABSTRACT: Upon signing a technology transfer agreement with Cornell University, ACCEL began producing turn-key 500 MHz superconducting cavity systems. Five such cryomodules have been delivered and commissioned to date. Four of them are installed in accelerators for operation (two in CESR and one each in Canadian Light Source and Taiwan Light Source) and one serves as an off-line spare at CLS. One more cryomodule is scheduled for testing in early 2005. It will be a spare unit for TLS. Three cryomodules for DIAMOND Light Source are being fabricated at ACCEL. The commissioning results and operational experience with the cryomodules in CESR, CLS and TLS are presented.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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ABSTRACT: The production of 6 superconducting 500 MHz modules for Cornell University, the Taiwan Light Source and the Canadian Light Source is almost finished. We summarize the vertical cavity test results and report on cold module tests. Operational experience with the delivered modules is also presented. Furthermore a 1.5 GHz superconducting Landau module is under production at ACCEL. The status of this project will be discussed.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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ABSTRACT: Effective cryomodule control and monitoring are essential components to successful operation of CESR (Cornell Electron Storage Ring). The ability to quickly diagnose system problems can have a dramatic effect on machine down time. The CESR SRF Digital Cryomodule control system, employing a PC and a commercial PLC and user interface, is presented. With these tools, system status is available at a glance or, if needed, detailed system information can be displayed. Straightforward configuration of PID (Proportional Integral Derivative) control loops, safety interlocks, signal display, and data acquisition is the main feature of the system. The SRF cryomodules have several modes of operation. For example, under normal machine running conditions, liquid helium level is regulated using a liquid-level signal as the process variable (PV). For cryostat cool-down, the flow rate of cold helium gas returning to the refrigerator directly reflects cryomodule cooling rate and is a more useful process variable. Both these operational modes use the same control variable (CV): the liquid helium supply valve control signal. Other operational modes include warm-up and RF processing. This control system can be reconfigured quickly to meet the conditions of different operational modes.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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S. Belomestnykh,
P. Barnes,
E. Chojnacki,
R. Ehrlich,
R. Geng,
D. Hartill,
R. Kaplan,
J. Knobloch,
E. Nordberg,
H. Padamsee,
S. Peck, P. Quigley,
J. Reilley,
D. Rubin,
J. Sears,
V. Veshcherevich
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ABSTRACT: The new superconducting RF system consisting of four single-cell
cavity modules is an important part of the CESR Luminosity Upgrade. We
describe the commissioning of the first three accelerating modules. This
includes in situ testing and conditioning, pulsed power and beam
processing of RF windows, commissioning of various cryogenic feedback
loops, measuring cavity spacing and phasing with beam, and high-current
operation
Particle Accelerator Conference, 1999. Proceedings of the 1999; 02/1999
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S. Belomestnykh,
P. Barnes,
E. Chojnacki,
R. Ehrlich,
W. Hartung,
T. Hays,
R. Kaplan,
J. Kirchgessner,
E. Nordberg,
H. Padamsee,
S. Peck, P. Quigley,
J. Reilly,
D. Rubin,
J. Sears
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ABSTRACT: After the successful CESR beam test of August 1994 the continued
development of a superconducting RF system for the CESR luminosity
upgrade is in progress at the Laboratory of Nuclear Studies, Cornell
University. The system description as well as recent results are
presented
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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S Belomestnykh,
Z Conway,
J Dobbins,
R Kaplan,
M Liepe, P Quigley,
J Reilly,
J Sikora,
C Strohman,
V Veshcherevich,
Classe
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ABSTRACT: Two high power 1300 MHz RF systems have been developed for the Cornell University ERL Injector. The first system, based on a 16 kWCW IOT transmitter, is to provide RF power to a buncher cavity. The second system employs five 120 kWCW klystrons to feed 2-cell superconducting cavities of the injector cryomodule. The sixth, spare klystron is used to power a deflecting cavity in a pulsed mode for beam diagnostics. A digital LLRF control stem was designed and implemented for precise regulation of the cavities' field amplitudes and phases. All components of these systems have been recently installed and commissioned. The first operational experience with the systems is discussed.
