TY - CONF AU - Kondo, Y. AU - Fang, Z. AU - Fukui, Y. AU - Futatsukawa, K. AU - Hirano, K. AU - Hori, T. AU - Ikegami, K. AU - Ishiyama, T. AU - Ito, T. AU - Ito, Y. AU - Kato, Y. AU - Kikuzawa, N. AU - Kitamura, R. AU - Kobayashi, F. AU - Miyao, T. AU - Morishita, T. AU - Nanmo, K. AU - Nemoto, Y. AU - Oguri, H. AU - Ohkoshi, K. AU - Otani, M. AU - Sato, Y. AU - Sawabe, Y. AU - Shibata, T. AU - Shinozaki, S. AU - Shinto, K. AU - Takahashi, D. AU - Tasaki, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Upgrade of the 3-MeV LINAC for Testing of Accelerator Components at J-PARC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We are now upgrading a 3-MeV linac at J-PARC. The old 30-mA RFQ is replaced by a spare one of the J-PARC 50-mA RFQ. The ion source is same as the J-PARC linac’s, therefore, the peak beam current is upgraded from 30 mA to 50 mA. This 3-MeV linac will be used for development of various accelerator components, such as beam dyagnostics devices, laser charge exchange equipments, new MEBT buncher, and so on. In this paper, present status of this 3-MeV test linac is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 960 EP - 963 KW - rfq KW - linac KW - operation KW - MMI KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS046 UR - http://jacow.org/ipac2019/papers/mopts046.pdf ER - TY - CONF AU - Miura, K. AU - Kuniyasu, Y. AU - Kurimoto, Y. AU - Morita, Y. AU - Naito, D. AU - Oogoe, T. AU - Ooya, K. AU - Sagawa, R. AU - Shimogawa, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Magnet Power Supply Calibration with a Portable Current Measuring Unit at the J-PARC Main Ring J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the J-PARC MR, 96 bending magnets (BMs) are used in total. They are divided into 6 groups of 16 BMs. The 16 BMs in each group are connected in series and driven by a single power supply. Since all 96 BMs are symmetrically located in the ring, the magnet currents regulated by the 6 power supplies need to be same. Each power supply performs output current feedback control using electronic circuits including analog amplifications and AD / DA conversions. Due to individual differences of the electronic circuits, output current is generally expected to be different for each power supply. Therefore, we developed a current measurement unit with the portable DCCT as an independent reference. Further, we measured the magnet currents regulated by the 6 BM power supplies using the unit. We report the details of the unit as well as the results of the current measurements. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1263 EP - 1265 KW - power-supply KW - feedback KW - operation KW - timing KW - controls DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP015 UR - http://jacow.org/ipac2019/papers/tupmp015.pdf ER - TY - CONF AU - Hashimoto, Y. AU - Endo, M. AU - Hori, Y. AU - Murakami, M. AU - Murashima, K. AU - Muto, R. AU - Sakai, H. AU - Tachibana, M. AU - Tatami, A. AU - Tomizawa, M. AU - Toyama, T. AU - Uota, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Profile Monitor for Slow Extracted Beam Using Multi-Layered Graphene at J-PARC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Extracted-beam profiles in slow extraction at J-PARC has been measured by using secondary electrons emitted from a target array made by multi-layered graphen, in real time during spill time of around 2 seconds. The target array consists of 20 ribbons with width of 1 mm, pitch of 2 mm, and thickness of 1.1 micron. Secondary-electron current at each channel is measured by a current amplifier having sensitivity more than 1 pA. These configuration produces useful information for beam dynamics in slow extraction. We have set this monitor at the entrance of a septum magnet, then we can also measure the last few-turns beam with the extracted beam simultaneously. We will discuss about features of this instrument and recent beam study with 51 kW extracted-beams. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2532 EP - 2535 KW - target KW - electron KW - extraction KW - proton KW - real-time DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW030 UR - http://jacow.org/ipac2019/papers/wepgw030.pdf ER - TY - CONF AU - Zhang, R. AU - Honda, Y. AU - Kumano, H.K. AU - Toyotomi, N. AU - Yoshida, M. AU - Zhou, X. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Hybrid Yb/Nd Laser System for RF Gun in SuperKEKB Phase II and Phase III Commissioning J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - SuperEKKB phase II commissioning has been finished in the summer of 2018. By use of Ytterbium doped fiber and Nd:YAG hybrid laser system, 2.3 nC electron beam with low emittance has been achieved at the end of linac, which is generated by RF gun. The electron beam is injected and stored in High Energy Ring successfully. Basing on these operation experiences, the Nd:YAG laser system will be used for the early stages of SuperKEKB phase III commissioning. After the update of laser system during 2018 summer maintenance, about 5.3 nC electron charge is generated by RF gun. Beside this, the laser spatial and temporal reshaping experiment has been being done in order to realize the electron beam with low emittance and low energy spread. Meanwhile, a perspective towards the next step Yb:YAG laser system is also introduced in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3663 EP - 3666 KW - laser KW - electron KW - gun KW - MMI KW - injection DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW037 UR - http://jacow.org/ipac2019/papers/thpgw037.pdf ER - TY - CONF AU - Takahashi, H. AU - Hatakeyama, S. AU - Ishiyama, T. AU - Miyao, T. AU - Sawabe, Y. AU - Suzuki, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Development of Beam Window Protection System for J-PARC Linac J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In J-PARC Linac, beam study (including beam conditioning) is mainly performed using beam dump. A beam window is installed in the beam line to each beam dump. It is considered that the parameters of acceptable beam　to able to be injected the beam window are the 50 mA current, the 100 micro-sec width and the 2.5 Hz repetition. On the other hand, at beam study of Linac, the beam with higher power than these parameters are not used. Therefore, the beam study was started and performed only after the operator checked that the beam parameters are within the acceptable values. However, at the beam study of 2018, a beam windows of 0-degree dump was cracked because the beam that exceeds acceptable parameters was injected due to human error. Then, beam study using 0-degree dump was impossible at all. And, in order not to cause such accident again, we began to develop the beam window protection system. Moreover, as soon as possible, implementation of the system was required. Therefore, we designed and developed this system by improving it based on the particle management system which can measure all 25 Hz beam. We have developed a beam window protection system that monitors the beam current for each shot and accumulated beam current for a prescribed time and inhibits the beam by MPS when either value exceeds the threshold. Moreover, we succeeded in developing and implementing this system in a short time. This paper is described about development and function test of beam window protection system. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3886 EP - 3889 KW - linac KW - operation KW - PLC KW - vacuum KW - site DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB035 UR - http://jacow.org/ipac2019/papers/thprb035.pdf ER -