| Paper |
Title |
Other Keywords |
Page |
| MO2001 |
Status of the CLIC Test Facility (CTF3)
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linac, acceleration, klystron, beam-loading |
11 |
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- G. Geschonke
CERN, Geneva
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The CTF3 project, being built within the frame-work of an international collaboration involving more than 12 institutions, is advancing as planned. To date, the electron linac with its sub-harmonic bunching system, the magnetic chicane for bunch-length variations, and the Delay Loop have been installed. The 1.5 GHz sub-harmonic bunching system with fast phase switching allows the longitudinal position of the bunches to be changed every 140 ns. This phase-coded beam has been successfully injected into the Delay Loop using an RF deflector and bunch interleaving of 140 ns long sub-bunch trains which double the bunch repetition frequency has been demonstrated in the extraction line. In addition to its role as a test bed for the CLIC RF power source, CTF3 is being used as a source of high-power RF at 30 GHz for the testing of CLIC accelerating structures. In this power-generating mode, about 100 MW of 30 GHz power is routinely extracted from the beam half-way up the linac by special-purpose power-extracting structures and transported to the high-gradient test area by low-loss waveguides. This paper describes the overall status of the CTF3 project and outlines the plans for the future.
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| TU1002 |
Technologies Toward a 100-kW Free-Electron Laser
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wiggler, electron, gun, emittance |
205 |
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- D. C. Nguyen
LANL, Los Alamos, New Mexico
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The challenges of a high-average-power (100 kW and above) FEL are not insurmountable. Some of these challenges however require technological solutions beyond the incremental improvements of existing mature technologies. Efforts are underway to develop novel technologies that could lead to a new level of FEL performance, e.g. 100-kW average power. These technologies include a high-average-current RF photo-injectors, spoke resonator RF cavities with energy recovery, high-gain amplifiers driven by high-brightness electron beams, beam-breakup instability suppression, and new concepts of tapered wiggler designs, e.g. stair-step taper, for efficient energy extraction. In this talk, these technologies, potential benefits and issues will be discussed.
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| TUP002 |
High-Dynamic-Range Current Measurements in the Medium-Energy Beta Transport Line at the Spallation Neutron Source
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SNS, Spallation-Neutron-Source, linac, rfq |
244 |
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- D. A. Bartkoski, A. V. Aleksandrov, D. E. Anderson, M. T. Crofford, C. Deibele, S. Henderson, J. C. Patterson, C. Sibley, A. Webster
ORNL, Oak Ridge, Tennessee
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It is desired to measure the effectiveness of the LEBT (low energy beta transport) chopper system. Since this chopper is required to chop the H- beam to a 1% level, it is required therefore to accurately measure the beam during the chop. A system is developed with a high dynamic range that can both accurately measure the beam to tune the chopper system as well as provide an input to the MPS (machine protection system) to stop the beam in the event of a chopper system failure. A system description, beam based calibration, and beam measurements are included.
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| TUP054 |
A Proposed Helicon Driver for the SNS Ion Source
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plasma, SNS, ion, ion-source |
367 |
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- R. F. Welton, R. H. Goulding, S. N. Murray, M. P. Stockli
ORNL, Oak Ridge, Tennessee
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The H- ion source employed in the Spallation Neutron Source* (SNS) is an RF-driven, multi-cusp source, which utilizes a helical antenna to inductively couple power into the source plasma. To date, the source has been successfully utilized in the commissioning of the SNS accelerator producing 10–40 mA of H- with duty-factors of ~0.1%. Ultimately, the SNS facility will require beam duty-factors of 6% and ~60 mA of H- injecting the linac. This may require currents of up to ~100 mA from the source depending on the ion source emittance. To date, the SNS source has only delivered sustained currents of ~33 mA at full duty factor. Therefore, we are developing plasma generators capable of achieving much higher plasma densities. Plasmas generated through helicon-wave coupling can develop densities up to 100 times greater than those produced by conventional inductive coupling. This report presents an initial design and discusses considerations for a source which combines the forward portion of the SNS source with a helicon system. The helicon system consists largely of components retrofitted from the proven hydrogen VASIMR system employed in space propulsion.
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| THP038 |
Normal Conducting High-Gradient Studies at KEK
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linear-collider, collider, acceleration, vacuum |
661 |
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- T. Higo, M. Akemoto, S. Fukuda, Y. Higashi, N. K. Kudo, S. Matsumoto, K. Takata, T. T. Takatomi, K. Ueno, K. Yokoyama
KEK, Ibaraki
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Normal-conducting high field studies have been pursued at XTF, a high power X-band RF facility of KEK developed for linear collider. Three traveling-wave structures developed for X-band linear collider were studied in high field of more than 70MV/m level. High-field characteristic such as field emission properties and trip rate, etc. are studied carefully as the processing proceeds. Operation at 50MV/m level was found very stable while breakdowns happened once an hour or so at more than 70MV/m, indicating the approach to some critical point. This characteristics is discussed in conjunction with various author’s trials to make a scaling law of severe breakdowns among power, pulse width and so on. Further basic studies on field/power limitation or robustness against breakdowns in various materials are planned using narrowed waveguide configuration. Unique features related to this study is also described.
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