Author: Oguri, H.
Paper Title Page
MOPME026 Beam Monitor Layout for Future ACS Section in J-PARC Linac 529
  • A. Miura, M. Ikegami, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. With this upgrade, the design peak current will be increased from the present 30 mA to 50 mA, and the energy from 181 MeV to 400 MeV. Along with these significant upgrades of the beam parameters, beam monitors should be followed. Also, the bunch shape monitor and new beam loss monitoring system will be employed for the new beam line. Newly fabricated devices will be delivered in the ACS beam line. And beam monitor layout of the upstream and downstream of ACS beam line will be modified. In this paper, we introduce the development of the beam diagnostic devices for the project and the new designed beam monitor layout.  
MOPME027 Bunch Length Measurement of 181 MeV Beam in J-PARC Linac 532
  • A. Miura, H. Oguri, N. Ouchi, J. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  • A. Feschenko, A.N. Mirzojan
    RAS/INR, Moscow, Russia
  • K. Futatsukawa, T. Miyao
    KEK, Ibaraki, Japan
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • T. Maruta
    KEK/JAEA, Ibaraki-Ken, Japan
  In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. Because the longitudinal matching before ACS cavities is additionally required, we decided to employ the bunch shape monitors (BSMs) to measure the longitudinal beam profile. After three years from the start of BSM project, three BSMs were fabricated. All three BSMs were installed during the summer shutdown of 2012. We tried to measure the longitudinal beam profile exited from SDTL cavities. In this paper, we introduce the outline of BSM project, the first data acquisition and related small problems.  
WEYB101 Power Upgrade of J-PARC Linac 2047
  • H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  A linac power upgrade program is now in progress after a successful recovery from the earthquake disaster. The power upgrade includes an ion source, an RFQ and a 400 MeV Annular-ring Coupled Structure (ACS) linac. We started a full-scale development of a cesium seeded RF-driven negative hydrogen ion source. The ion source extracted the beam of more than 60 mA with a duty factor of 2.5 %, which is satisfied with the requirement of the program. A new RFQ for 50 mA acceleration is under construction on the basis of a RFQ fabrication process, which was built as a backup for the present RFQ. Mass production of the ACS modules have almost completed. There is a plan to install these components and schedule the beam test in 2013. This presentation will cover the power upgrade status of the J-PARC linac.  
slides icon Slides WEYB101 [4.205 MB]  
THPWO031 Status of J-PARC Accelerators 3830
  • K. Hasegawa, M. Kinsho, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Koseki
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  After nine-months of beam shutdown by the Great Earthquake in March 2011, the J-PARC facility resumed beam operation. In December 2011, operations were carried out at low duty such as single-shots or 1 to 2.5 Hz for beam tuning. At the beginning of January 2012, we started beam tuning at the full repetition rate of 25 Hz at the linac and the 3 GeV Rapid Cycling Synchrotron (RCS). After the tuning, user programs of the Materials and Life Science Experiment Facility (MLF), the Neutrino facility and the Hadron facility started. The beam power was increased from 100 to 300 kW to the MLF users, from 3.3 kW to 6 kW to the Hadron users, and from 140 to 200 kW to the Neutrino users. The beam availability went lower to 73 % in JFY 2011 due to the trouble of the linac klystron power supply in March, but it has got back to 90-94 % as of November in JFY2012. We have also much upgrade work during the shutdown period or in parallel to the operation. We’ve demonstrated new record power beyond 500kW from the RCS. The status and progress of the J-PARC accelerators are presented.  
THPWO034 Fabrication of the RFQ III for the J-PARC Linac Current Upgrade 3839
  • T. Morishita, Y. Kondo, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • K. Hasegawa
    JAEA, Ibaraki-ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
  The J-PARC accelerator comprises an injector linac, a 3-GeV Rapid-Cycling Synchrotron and a 50-GeV Main Ring. The J-PARC linac has been operating for users with the beam energy of 181 MeV. The energy (to 400MeV) and current (to 50mA) upgrade of the linac is scheduled for 1MW operation at RCS. For the current upgrade, the RFQ III, which is designed for 50mA beam acceleration, has been fabricated. The engineering design and the fabrication technologies are basically the same as the RFQ II in J-PARC linac. Some engineering methods are improved for the dimension accuracy, the reliability, and the period of fabrication. In the RFQ II fabrication, there was a leakage trouble at the electron-beam-welding spot by the thermal stress at the brazing only occasionally. Then, we changed to all-brazing design. Also, there was a vane deformation after the final machining. This was corrected by changing the method of fixation at the brazing. As a result, a dimension error was in a tolerable range. Currently, the fabrication is in a final process and the high-power test is scheduled at the second quarter of 2012.