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Ishikado, Motoyuki*; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ishimaru, Sora*; Yamauchi, Sara*; Kawamura, Seiko; Kira, Hiroshi*; Sakaguchi, Yoshifumi*; Watanabe, Masao; et al.
JPS Conference Proceedings (Internet), 41, p.011010_1 - 011010_7, 2024/05
Hasemi, Hiroyuki; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Ishikado, Motoyuki*; Kawamura, Seiko; Komine, Ryota
JPS Conference Proceedings (Internet), 41, p.011003_1 - 011003_5, 2024/03
Kaneko, Koji; Tabata, Chihiro; Hagihara, Masato; Yamauchi, Hiroki; Oba, Yojiro; Kumada, Takayuki; Kubota, Masato; Kojima, Yuki*; Nabatame, Nozomi; Sasaki, Miki; et al.
JPS Conference Proceedings (Internet), 41, p.011015_1 - 011015_6, 2024/03
Shimoda, Ami*; Iwasa, Kazuaki*; Kuwahara, Keitaro*; Sagayama, Hajime*; Nakao, Hironori*; Ishikado, Motoyuki*; Ohara, Takashi; Nakao, Akiko*; Hoshikawa, Akinori*; Ishigaki, Toru*
JPS Conference Proceedings (Internet), 38, p.011091_1 - 011091_6, 2023/05
Takahama, Ryusei*; Arizono, Mitsutoshi*; Indo, Daigo*; Yoshinaga, Taisei*; Terakura, Chieko*; Takeshita, Nao*; Shirasaki, Takumi*; Noda, Masaaki*; Kuwahara, Hideki*; Kajimoto, Ryoichi; et al.
JPS Conference Proceedings (Internet), 38, p.011114_1 - 011114_6, 2023/05
Onishi, Hiroaki; Miyashita, Seiji*
JPS Conference Proceedings (Internet), 38, p.011157_1 - 011157_6, 2023/05
Chen, Y.*; Asano, Shun*; Wang, T.*; Xie, P.*; Kitayama, Shinnosuke*; Ishii, Kenji*; Matsumura, Daiju; Tsuji, Takuya; Taniguchi, Takanori*; Fujita, Masaki*
JPS Conference Proceedings (Internet), 38, p.011050_1 - 011050_6, 2023/05
Kubo, Katsunori
JPS Conference Proceedings (Internet), 38, p.011161_1 - 011161_6, 2023/05
Saha, P. K.; Harada, Hiroyuki; Kinsho, Michikazu; Yoneda, Hitoki*; Michine, Yurina*; Fuchi, Aoi*; Sato, Atsushi*; Liu, Y.*
JPS Conference Proceedings (Internet), 33, p.011025_1 - 011025_7, 2021/03
Tsuchikawa, Yusuke; Abe, Yuta; Oishi, Yuji*; Kai, Tetsuya; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Kimura, Atsushi; Nakamura, Shoji; Harada, Masahide; et al.
JPS Conference Proceedings (Internet), 33, p.011074_1 - 011074_6, 2021/03
In the decommissioning of the Fukushima-Daiichi (1F) Nuclear Power Plant, it is essential to understand characteristics of the melted core materials. The estimation of boride in the real debris is of great importance to develop safe debris removal plans. Hence, it is required to investigate the amount of boron in the melted core materials with nondestructive methods. Prompt gamma-ray activation analysis (PGAA) is one of the useful techniques to determine the amount of borides by means of the 478 keV prompt gamma-ray from neutron absorption reaction of boron. Moreover, it is well known that the width of the 478 keV gamma-ray peak is typically broadened due to the Doppler effect. The degree of the broadening is affected by coexisting materials, and can be recognized by the width of the prompt gamma-ray peak. As a feasibility study, the prompt gamma-ray from boride samples were measured using the ANNRI, NOBORU, and RADEN beamlines at the Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Complex (J-PARC).
Kitamura, Ryo; Futatsukawa, Kenta*; Hayashi, Naoki; Hirano, Koichiro; Kondo, Yasuhiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Nemoto, Yasuo*; Morishita, Takatoshi; Oguri, Hidetomo
JPS Conference Proceedings (Internet), 33, p.011012_1 - 011012_6, 2021/03
The new bunch shape monitor (BSM) is required to measure the bunch size of the high-intensity H beam with 3 MeV at the front-end section in the J-PARC linac. The carbon-nano tube wire and the graphene stick are good candidates for the target wire of the BSM, because these materials have the enough strength to detect the high-intensity beam. However, since the negative high voltage of more than a few kV should be applied to the wire in the BSM, the suppression of the discharge is the challenge to realize the new BSM. After the high-voltage test to investigate the effect of the discharge from the wire, the detection of the signal from the BSM was successful at the beam core with the peak current of 55 mA using the graphene stick. The preliminary result of the bunch-size measurement is reported in this presentation.
Abe, Yuta; Tsuchikawa, Yusuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Oishi, Yuji*; Kamiyama, Takashi*; Nagae, Yuji; Sato, Ikken
JPS Conference Proceedings (Internet), 33, p.011075_1 - 011075_6, 2021/03
Nakamura, Tatsuya; Kawasaki, Takuro; To, Kentaro; Harjo, S.; Sakasai, Kaoru; Aizawa, Kazuya
JPS Conference Proceedings (Internet), 33, p.011097_1 - 011097_6, 2021/03
A large area, two-dimensional scintillation neutron detector was developed for Takumi diffractometer in the J-PARC MLF. The detector is made based on a scintillator/wavelength shifting fiber technology. The detector has a neutron-sensitive area of 32 32 cm with a pixel size of 5
5 mm, which is about 1.5-fold larger than the SENJU detector TAKUMI is one of the neutron diffractometers in the MLF dedicated to use for engineering material research. The developed detector array adds new capabilities to the instrument to measure two-dimensional data collection at the back-scattering angles with a better time-of-flight resolution.
Miyazaki, Yasunori; Watanabe, So; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori; Kai, Tetsuya; Parker, J. D.*
JPS Conference Proceedings (Internet), 33, p.011073_1 - 011073_7, 2021/03
Neutron resonance absorption imaging was adapted to observe the Eu band adsorbed in the CMPO/SiO-P column for minor actinide recovery by extraction chromatography. Several wet columns were prepared by either light water or heavy water and compared with the dry column to evaluate the neutron transmission. The neutron transmission spectra showed that 45% was transmitted through the dry column while 20% and 40% were transmitted through the wet columns of light water and heavy water, respectively. The results indicated that heavy water is more applicable than light water to observe the Eu adsorption band in the CMPO/SiO
-P column.
Harada, Masahide; Sakai, Motonobu*; Kurosawa, Takashi*; Haga, Katsuhiro
JPS Conference Proceedings (Internet), 33, p.011098_1 - 011098_5, 2021/03
Materials and Life science experimental Facility (MLF) in J-PARC has a high-intense spallation neutron source and a high-intense muon source induced by 3-GeV and 1MW proton beam. To reduce beam loss, components of proton, neutron and muon beam lines are precisely aligned. However, a settlement of MLF caused by a building construction, installation of heavy shields, earthquakes, consolidation of basement, instrument installation (weight increase), and so on, was assumed in the design stage. Therefore, periodic level measurements in MLF was started from the design stage. A few tens of level measuring points are installed inside and outside MLF. The level measurements were done once per month in the construction stage and per year after operation start. In the construction stage of MLF, it was found that the MLF building largely settled by construction of the building and installation of many shields. And it was also found that The Great East Japan Earthquake on March 11, 2011, caused large settlements of MLF attached buildings. Figure 1 shows fluctuations of measured levels at representative points in each area from December 2011. No critical deterioration (small changes within 1.0 mm) could be detected. However, a few local settlements are found in the MLF building. In the presentation, periodic level measurement results at MLF will be introduced.
Oikawa, Kenichi; Harjo, S.; Pham, A. H.*; Kawasaki, Takuro; Morito, Shigekazu*; Kiyanagi, Yoshiaki*; Shinohara, Takenao; Kai, Tetsuya; Oba, Takuya*; Ito, Masakazu*
JPS Conference Proceedings (Internet), 33, p.011062_1 - 011062_6, 2021/03
Sakai, Kenji; Oi, Motoki; Haga, Katsuhiro; Kai, Tetsuya; Nakatani, Takeshi; Kobayashi, Yasuo*; Watanabe, Akihiko*
JPS Conference Proceedings (Internet), 33, p.011151_1 - 011151_6, 2021/03
For safely and efficiently operating a spallation neutron source and a muon target, a general control system (GCS) operates within Materials and Life Science Experimental Facility (MLF), GCS administers operation processes and interlocks of many instruments for various operation statuses. It consists of several subsystems such as an integral control system (ICS), interlock systems (ILS), shared servers, network system, and timing distribution system (TDS). Although GCS is an independent system that controls the target stations, it works closely with the control systems of other facilities in J-PARC. Since the first beam injection in 2008, GCS has operated stably without any serious troubles after modification based on commissioning for operation and control. Then, significant improvements in GCS such as upgrade of ICS by changing its framework software and function enhancement of ILS were proceeded until 2015, in considering sustainable long-term operation and maintenance. In recent years, many instruments in GCS have replaced due to end of production and support of them. In this way, many modifications have been proceeded in the entire GCS after start of beam operation. Under these situation, it is important to comprehend upgrade history and present status of GCS in order to decide its upgrade plan for the coming ten years. This report will mention upgrade history, present status and future agenda of GCS.
Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kakurai, Kazuhisa*; Shimizu, Hirohiko*; Hirota, Katsuya*; et al.
JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03
In neutron fundamental physics, study of correlation term of a neutron spin
and a target nuclear spin
is important because
term interferes to parity non-conserving (PNC) and time reversal non-conserving terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to
by using a spin exchange optical pumping (SEOP) method. We would plan to develop a polarized Xe gas target with a compact in-situ SEOP system, and to study
term by utilizing epithermal neutron beams supplied from a high intense pulsed spallation neutron source. As the first step, we attempted to measure neutron polarizing ability caused by
term at a 9.6 eV s-wave resonance peak of
Xe at BL10 in MLF, by detecting change
of ratio between neutron transmissions with the polarized and unpolarized Xe target. After demonstrating that our apparatus could detect small change (
) of neutron transmissions caused by Doppler broadening effect, a signified value of
has been obtained as preliminary results. For analyzing the obtained
in detail, we are improving our nuclear magnetic resonance and electron paramagnetic resonance systems for evaluating Xe polarization independently of neutron beams.
Kamiya, Junichiro; Kotoku, Hirofumi; Hikichi, Yusuke*; Takahashi, Hiroki; Yamamoto, Kazami; Kinsho, Michikazu; Wada, Kaoru*
JPS Conference Proceedings (Internet), 33, p.011023_1 - 011023_6, 2021/03
The vacuum system is the key for the stable high power beam operation in J-PARC 3 GeV rapid cycling synchrotron (RCS), because the gas molecules in the beam line make the beam loss due to the scattering. The more than 10 years operation of the RCS vacuum system showed that the ultra-high vacuum (UHV) has been stably maintained by the several developments. The challenges for lower beam line pressure will exist in a future operation with higher beam power. For such challenge, a TMP with a rotor of titanium alloy, which have much higher mechanical strength than aluminum allow for the normal rotter, has been developed. Overcoming the difficulties of the machining performance of the titanium alloy rotor was successfully manufactured. We will report the summary of the 10 years operation of the RCS vacuum system and the incoming developments towards the XHV.
Maekawa, Fujio
JPS Conference Proceedings (Internet), 33, p.011042_1 - 011042_6, 2021/03
Development of beam window (BW) materials is one of crucial issues in development of accelerator driven nuclear transmutation systems (ADS). The BW is exposed to high energy protons and spallation neutrons, and also to corrosive lead-bismuth eutectic (LBE) alloy at high temperature of about 500C. Recently, not only high-power accelerators but also high-power targets are the rate-limiting factor for increasing the power of accelerator facilities in terms of radiation damage and heat removal. To study radiation damage on BW and target materials for high-power accelerator facilities including ADS, we are planning a materials irradiation facility by utilizing the proton beam of 400 MeV and 250 kW provided by the J-PARC's Linac. The target is flowing LBE alloy which is a candidate target and coolant material of ADS. When a steel sample is irradiated in the target for one year, the sample receives radiation damage of about 10 dpa at maximum which is equivalent to the yearly radiation damage of ADS's BW. In the current facility concept, the facility is equipped with a hot-laboratory for efficient post-irradiation examination. The facility will be outlined in this presentation.