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Title |
Page |
TPPT041 |
RF Tuning and Fabrication Status of the First Module for J-PARC ACS
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2684 |
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- H. Ao, T. Morishita, A. Ueno
JAERI/LINAC, Ibaraki-ken
- K. Hasegawa
JAERI, Ibaraki-ken
- M. Ikegami
KEK, Ibaraki
- V.V. Paramonov
RAS/INR, Moscow
- Y. Yamazaki
JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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J-PARC Linac starts with 180-MeV SDTL temporary, and it is upgraded to 400-MeV with 21 ACS (Annular Coupled Structure) modules and two ACS bunchers and two debunchers. First buncher module is under fabrication, and second buncher and a few accelerating modules are also planed until FY2006. The first ACS module consists of two 5-cells ACS tanks and a 5-cells bridge cavity for the buncher module. Three RF tuners are installed to the bridge cavity for fine RF tuning. An operating frequency should be tuned to 972 MHz within the fine-tuning range before a brazing process in a factory. The tuning procedure has been studied with RF simulation analysis and cold-model measurements for ACS and bridge cells. This paper describes RF tuning results, fabrication status and related development items.
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WPAE044 |
An Alignment of J-PARC Linac
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2851 |
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- T. Morishita, H. Ao, T. Ito, A. Ueno
JAERI/LINAC, Ibaraki-ken
- K. Hasegawa
JAERI, Ibaraki-ken
- M. Ikegami, C. Kubota, F. Naito, E. Takasaki, H. Tanaka, K. Yoshino
KEK, Ibaraki
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J-PARC linear accelerator components are now being installed in the accelerator tunnel, whose total length is more than 400 m including the beam transport line to RCS (Rapid Cycling Synchrotron). A precise alignment of accelerator components is essential for a high quality beam acceleration. In this paper, planned alignment schemes for the installation of linac components, the fine alignment before beam acceleration, and watching the long term motion of the building are described. Guide points are placed on the floor, which acts as a reference for the initial alignment at the installation and also as a relay point for the long surveying network linking at the fine alignment. For a straight line alignment, the wire position sensor is placed on the offset position with respect to the beam center by a target holder, then a single wire can cover the accelerator cavities and the focusing magnets at the DTL-SDTL section (120m). The hydrostatic levering system (HLS) is used for watching the floor elevation (changes) over the long period.
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ROPC002 |
J-PARC Commissioning Results
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220 |
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- K. Hasegawa
JAERI, Ibaraki-ken
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The J-PARC (Japan Proton Accelerator Research Complex)comprises a 400-MeV linac, a 3-GeV rapid-cycling synchrotron (RCS), a 50-GeV main ring synchrotron (MR) and experimental facilities. A peak current of 30 mA was accelerated up to 20 MeV of the DTL beam commissioning at the KEK site. The buildings and conventional facilities will be completed in succession in the Japanese Fiscal Year 2005, when the installation of the accelerator components will be actually started at Tokai site. The beam commissioning of the 181 MeV linac will be started in September, 2006, followed by the RCS and MR beam commissioning. To achieve the high beam power with low beam loss, the J-PARC accelerators are based on many newly developed technologies; pi-mode stabilizing loops in the RFQ, RF choppers in the medium energy beam transport, magnetic alloy loaded RF cavities in the synchrotrons, etc. The recent results of the developments of these new technologies, the present construction status and the commissioning schedule will be presented.
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FPAE043 |
Transverse Tuning Scheme for J-PARC Linac
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2750 |
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- M. Ikegami, Z. Igarashi, S. Lee
KEK, Ibaraki
- H. Akikawa, K. Hasegawa, Y. Kondo, T. Ohkawa
JAERI, Ibaraki-ken
- H. Ao, S. Sato, T. Tomisawa, A. Ueno
JAERI/LINAC, Ibaraki-ken
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In a high-intensity linac, precise transverse matching is essential for beam halo mitigation. In this paper, we present the supposed transverse tuning scheme for J-PARC linac and the planned beam diagnostic layout for it. Relevantly, we briefly touch upon the tuning scenario for the arc section and the transverse halo collimator system which are located between the linac and the succeeding ring.
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