Paper | Title | Page |
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TPPT009 | High Gradient Study at KEK on X-Band Accelerator Structure for Linear Collider | 1162 |
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We have fabricated accelerator structures for linear collider of the warm X-band design. These were composed of high-precision-machined parts for reliable wake-field suppression and possible cheap mass production. The structure design is mostly based on GLC/NLC design in collaboration with SLAC but the fabrication and the high-power test are being performed at KEK to conclude the feasibility, though the application to the present linear collider project was terminated. In this paper are presented the high gradient performance of these structures, such as the initial conditioning characteristics, the stability under high-field operation and various characteristics at high-gradient operation. We conclude that the stability requirement for the linear collider of the warm X-band design is barely satisfied but the preservation of the stability over very long period of more than several years is to be further studied. | ||
ROAC004 | High Gradient Performance of NLC/GLC X-Band Accelerating Structures | 372 |
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Funding: Work Supported by DOE Contract DE-AC02-76F00515. During the past five years, there has been an concerted effort at FNAL, KEK and SLAC to develop accelerator structures that meet the high gradient performance requirements for the Next Linear Collider (NLC) and Global Linear Collider (GLC) initiatives. The structure that resulted is a 60-cm-long, traveling-wave design with low group velocity (< 4% c) and a 150 degree phase advance per cell. It has an average iris size that produces an acceptable short-range wakefield in the linacs, and dipole mode damping and detuning that adequately suppresses the long-range wakefield. More than eight such structures have operated over 1000 hours at a 60 Hz pulse rate at the design gradient (65 MV/m) and pulse length (400 ns), and have reached breakdown rate levels below the limit for the linear collider. Moreover, the structures are robust in that the breakdown rates continue to decrease over time, and if the structures are briefly exposed to air, the rates recover to their low values within a few days. This paper presents a final summary of the results from this program, which effectively ended last August with the selection of cold technology for a next generation linear collider. |
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RPPP003 | Proposal of the Next Incarnation of Accelerator Test Facility at KEK for the International Linear Collider | 874 |
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The realization of the International Linear Collider (ILC) will require the ability to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittancies are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 35nm beam size. Such a facility would enable the development of beam diagnostics and tuning methods, as well as the training of young accelerator physicists. |