Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ao, Hiroyuki; Hirano, Koichiro; Morishita, Takatoshi; Asano, Hiroyuki; Naito, Fujio*; Ueno, Akira; Ikegami, Masanori*; Hasegawa, Kazuo; Yamazaki, Yoshishige; Paramonov, V.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.494 - 496, 2008/00
The J-PARC ACS cavity consists of many cell parts. For the mass production, the ACS requires about 1300 cell parts, so that it is important to reduce the machining time. In the previous ACS model, it took about three hours per one coupling slot. We, therefore, optimized the slot design, the tolerance, and the machining process. As a result, the machining time reduced to forty-five minutes per one slot. The four test cells were fabricated to measure the frequencies and Q-values, and these results were compared with the electromagnetic analysis with the Microwave Studio. Between the analysis and the measurement, the differences are 1
1.5 MHz and 45 MHz, respectively, for the accelerating mode, and for the coupling mode.
Ao, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Paramonov, V.*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2684 - 2686, 2005/00
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-cell ACS tanks and a 5-cell 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.
Ao, Hiroyuki; Akikawa, Hisashi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Noguchi, Shuichi*; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.75 - 77, 2004/00
The J-PARC (Japan Proton Accelerator Research Complex) LINAC will be commissioned with energy of 181-MeV using 50-keV ion source, 3-MeV RFQ, 50-MeV DTL and 181-MeV SDTL (Separated DTL) on September 2006. It is planed to be upgraded by using a 400-MeV ACS (Annular Coupled Structure), which is a high-beta structure most suitable for the J-PARC, in a few years from the commissioning. The first ACS type cavity, which will be used as the first buncher between the SDTL and the ACS, is under fabrication. Detailed design and tuning procedure of ACS cavities has been studied with RF simulation analysis and cold-model measurements. The results of cold-model measurements, fabrication status, and related development items are described in this paper.
Ao, Hiroyuki; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 2003 Particle Accelerator Conference (PAC 2003) (CD-ROM), p.2826 - 2828, 2003/00
An Annular Coupled Structure (ACS) has been developed for upgrade of a J-PARC (Japan Proton Accelerator Research Complex) linac from 180 MeV to 400 MeV. Although install area is prepared for the ACS cavities at an initial construction, it will be used as a beam-transport line temporarily. Aluminum and copper models were fabricated for RF properties confirmation based on an initial design, and for final optimization. RF measurement procedure of the ACS structure was also studied thorough the R&D process. Many items should be considered for mass production; schedule, handling parts, utilities, and so on. The measurement results of models and some fabrication status are presented.
Yamazaki, Yoshishige; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 21st International Linac Conference, p.752 - 754, 2003/00
The power-handling capability is the critical issue for a high intensity proton linac of normal-conducting coupled-cavity type. In the JAERI/KEK Joint Project, a coupled-cavity linac with the Annular Coupled Structure (ACS) has been developed in order to operate with 3 % duty factor. The ACS accelerating module consists of two ACS tanks and one bridge coupler. The cooling water circuits in the ACS cells ensure the effective and uniform cooling, stabilizing the deviation of cell frequencies. Some of excited cells in the bridge coupler are equipped with fast movable tuners to tune the cavity to the operating frequency. The results of thermal and structural analysis are presented, together with the RF parameter analysis, for different linac regimes. For the adopted ACS module design, the results of the analyses suggest that the operation with the heat loading of up to 90 kW/m is possible, which is corresponding to the 15 % duty factor operation.
Joshi, S. C.*; Paramonov, V.*; Skassyrskaya, A.*; Hayashizaki, Noriyosu*; Ikegami, Masanori*; Yamazaki, Yoshishige
Proceedings of 21st International Linac Conference, p.216 - 218, 2003/00
The normal conducting coupled-cavity linac with the Annular Coupled Structure (ACS) is adopted for 190-400 MeV part of high intensity proton linac for the JAERI/KEK Joint Project. The operating frequency is 972 MHz and the 23 modules will be constructed. The basic configuration is based on that investigated for L-band (1296 MHz) in the previous Japan Hadron Project research. However, the structure design is revised and optimized in order to meet requirements of reliability, operation efficiency and cost reduction for the newly proposed Joint Project. As the results of development, the transverse dimensions of the ACS tank are reduced sufficiently with the improvement in RF characteristics. The structure segmentation and essential points of the design are described.
Hayashizaki, Noriyosu*; Ao, Hiroyuki; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Kato, Takao*; Paramonov, V.*
Proceedings of 21st International Linac Conference, p.234 - 236, 2003/00
The normal conducting coupled-cavity linac with the Annular Coupled Structure (ACS) is adopted for 190-400 MeV part of high intensity proton linac for the JAERI/KEK Joint Project. The operating frequency is 972 MHz and the 23 modules will be constructed. The basic configuration is based on that investigated for L-band (1296 MHz) in the previous Japan Hadron Project research. However, the structure design is revised and optimized in order to meet requirements of reliability, operation efficiency and cost reduction for the newly proposed Joint Project. As the results of development, the transverse dimensions of the ACS tank are reduced sufficiently with the improvement in RF characteristics. The structure segmentation and essential points of the design are described.
Ao, Hiroyuki; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 21st International Linear Accelerator Conference, p.82 - 84, 2003/00
Annular Coupled Structure (ACS) has been developed for the 190-400MeV coupled-cavity linac of the JAERI/KEK joint project. Design optimization of the ACS cavity has nearly been completed using 2D and 3D codes. In parallel with the numerical analyses, half-scale aluminum models were fabricated to confirm the numerical results. The cold-model tests also aim to finish the detailed design taking mass production procedures into account. Especially, the machining and the tuning procedures are examined in detail from the viewpoint of cost reduction and quality management. The results of the model tests are presented with those of other recent R&D works on ACS, which include fabrication R&D performed with full-scale models.