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Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.
Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10
Times Cited Count:167 Percentile:97.27(Physics, Multidisciplinary)An isotope of the 113th element, 113, was produced in a nuclear reaction with a Zn beam on a Bi target. We observed six consecutive decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of Db and Lr both in decay energies and decay times. This indicates that the present decay chain consisted of 113, Rg (Z = 111), Mt (Z = 109), Bh (Z = 107), Db (Z = 105), and Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope 113, of the 113th element.
Kabumoto, Hiroshi; Takeuchi, Suehiro; Ishizaki, Nobuhiro; Yoshida, Takahiro*; Ishiguro, Takayuki*; Yamaguchi, Kazushi*
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.1120 - 1122, 2010/03
The JAEA-Tokai tandem accelerator was built for basic science researches with heavy ions. Its superconducting booster was completed in 1994 for increasing the acceleration energy of ions. The booster consists of 40 superconducting acceleration resonators and 10 cryostats. Every resonator is a coaxial quarter wave resonator (QWR) of which frequency is 129.8MHz, and optimum beam velocity is 10% of the light velocity. When it was built, the acceleration field gradients of superconducting resonators were 5.0MV/m at RF power input of 4W on their average. The performance decrease little by little, and it become 4.0MV/m now. Some of the resonators generate X-rays from a low electric field. A field emission will be occurred from small contaminations accumulated on the surfaces of niobium. We examined the high pressure water jet rinsing (HPWR) to re-recondition the superconducting booster. The HPWR is the technology of removing small contaminations on resonator surfaces, and very effective for the improvement of acceleration field gradients. The acceleration field gradients of 20 on-line resonators were improved from 4.4MV to 5.7MV on their average.
Kabumoto, Hiroshi; Takeuchi, Suehiro; Ishizaki, Nobuhiro; Yoshida, Takahiro*; Ishiguro, Takayuki*; Yamaguchi, Kazushi*
Dai-22-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.129 - 132, 2010/01
The JAEA-Tokai tandem accelerator was built for basic science researches with heavy ions. Its superconducting booster was completed in 1994 for increasing the acceleration energy of ions. The booster consists of 40 superconducting acceleration resonators and 10 cryostats. Every resonator is a coaxial quarter wave resonator (QWR) of which frequency is 129.8 MHz, and optimum beam velocity is 10% of the light velocity. When it was built, the acceleration field gradients of superconducting resonators were 5.0 MV/m at RF power input of 4 W on their average. The performance decrease little by little, and it become 4.0 MV/m now. Some of the resonators generate X-rays from a low electric field. A field emission will be occurred from small contaminations accumulated on the surfaces of niobium. We examined the high pressure water jet rinsing (HPWR) to re-recondition the superconducting booster. The HPWR is the technology of removing small contaminations on resonator surfaces, and very effective for the improvement of acceleration field gradients. The acceleration field gradients of 20 on-line resonators were improved from 4.4 MV to 5.7 MV on their average.
Matsuda, Makoto; Takeuchi, Suehiro; Tsukihashi, Yoshihiro; Hanashima, Susumu; Abe, Shinichi; Osa, Akihiko; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; et al.
Dai-19-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.9 - 12, 2007/01
no abstracts in English
Kabumoto, Hiroshi; Takeuchi, Suehiro; Matsuda, Makoto; Iijima, Akihiko*; Yoshida, Takahiro*; Usami, Takahiro*; Hida, Tetsushi*
Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.819 - 821, 2006/00
JAEA and KEK have started acceleration of radioactive nuclear beam (RNB) and stable ion beam (SNB) from TRIAC. RNB and SNB are accelerated by SCRFQ and IH linac up to the energy of 1.1MeV/u. We were planning to re-accelerate the beams in the future by superconducting booster up to an energy of 58MeV/u. In order to inject the beams into superconducting booster, we need a pre-booster which is capable of acceleration from 1.1MeV/u to 2.0MeV/u. We have started development of superconducting twin quarter wave resonator (twin-QWR) in FY2004, and have fabricated a prototype twin-QWR in FY2005.
Matsuda, Makoto; Takeuchi, Suehiro; Tsukihashi, Yoshihiro; Horie, Katsuzo*; Ouchi, Isao*; Hanashima, Susumu; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; et al.
Dai-18-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.11 - 14, 2005/11
no abstracts in English
Matsuda, Makoto; Takeuchi, Suehiro; Tsukihashi, Yoshihiro; Horie, Katsuzo; Ouchi, Isao; Hanashima, Susumu; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; et al.
Dai-17-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.1 - 4, 2004/00
no abstracts in English
Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Yoshida, Tadashi
Nuclear Instruments and Methods in Physics Research A, 513(3), p.429 - 438, 2003/11
Times Cited Count:3 Percentile:27.69(Instruments & Instrumentation)At the JAERI Tandem accelerator, an acceleration tube replacing plan is proceeding to increase the acceleration voltage toward 20 MV. Lengthy conditioning is generally necessary for a large tube system. We had an idea to clean the tubes with high-pressure water-jet rinsing before installation. We cleaned tubes and tested them at 1 MV and 3 MV. The both results exhibited that the voltages went beyond the rated voltages and discharge activities were much less than the old records. During the test of new tubes at 3 MV, the conditioning proceeded well and an extremely stable condition was fulfilled within 24 hours. In conclusion, the cleaning was found to be a very promising way to improve high-voltage performance of the tubes in a large tube system.
Yoshida, Tadashi; Kanda, Susumu; Takeuchi, Suehiro; Horie, Katsuzo; Ouchi, Isao; Tsukihashi, Yoshihiro; Hanashima, Susumu; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; et al.
Dai-15-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.51 - 53, 2003/03
no abstracts in English
Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Ishizaki, Nobuhiro; Matsuda, Makoto; Tsukihashi, Yoshihiro; Kanda, Susumu; Tayama, Hidekazu; Abe, Shinichi; Yoshida, Tadashi
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.308 - 310, 2003/00
no abstracts in English
Azuma, Masaki*; Saito, Takashi*; Ishiwata, Shintaro*; Yoshida, Hirofumi*; Takano, Mikio*; Kosaka, Yuki*; Takagi, Hidenori*; Utsumi, Wataru
Journal of Physics; Condensed Matter, 14(44), p.11321 - 11324, 2002/11
Times Cited Count:11 Percentile:50.72(Physics, Condensed Matter)no abstracts in English
Nishikawa, Takeichiro*; Yoshida, Takashi*; Horikawa, Hiroshi*; Li, G.*; Isowaki, Yosuke*; Harada, Yasuhiro*; Nagai, Yuki; Itakura, Mitsuhiro
no journal, ,
no abstracts in English