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Maekawa, Fujio; Oikawa, Kenichi; Tamura, Masaya; Harada, Masahide; Ikeda, Yujiro; Watanabe, Noboru
LA-UR-06-3904, Vol.1, p.129 - 138, 2006/06
Total 23 neutron beam-lines will be installed for JSNS in the J-PARC project. One of them is assigned for the Materials and Life Science Facility (MLF), and the MLF will construct a neutron beam-line to demonstrate and monitor neutronic performance of JSNS. The neutron beam-line was accordingly named as "Neutron Beam-line for Obserbation and Research Use (NOBORU)". Major parts of the NOBORU, i.e., beam ducts, shield, a beam stop, slits, a cabin for measurement, a pillar crane, a sample table, etc., have been ordered in March 2004, and installation will be completed in 2007. A T0 chopper, a frame-overlap chopper, detector systems, samples, etc. will be ordered later on. The sample position is at 14 m from the decoupled moderator. Approximate sample room dimensions are 3 
2.5 m in area and 3 m in height. A shield structure was determined by shielding calculations in which detailed 3-D structure was considered. The design of NOBORU will be presented in the session.
Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Yamaguchi, Yuji; Oikawa, Kenichi; Tsuchikawa, Yusuke; Haga, Katsuhiro
no journal, ,
At J-PARC 1MW spallation neutron source, pulsed neutrons included by 25Hz pulsed proton beam are provided to neutron instruments. Recently, 800 kW proton beam operation is successful, and the proton beam power gradually increases. A neutron instrument observed neutron beams with weak time correction to proton pulse. Therefore, at the neutron instrument to measure neutron pulse characteristics, NOBORU, we tried to measure delayed neutrons. In the measurement, a neutron detector was located on the beam axis in the NOBORU experimental room and pulsed neutrons were measured with flight time after the beam operation stop. Pulse height was also measured to distinguish whether neutron or others. From the results, neutrons could be measured after the beam operation stop. We will present in details in the conference.
Harada, Masahide; Yamaguchi, Yuji; Takata, Shinichi; Oikawa, Kenichi; Oku, Takayuki
no journal, ,
Neutron monitors used in neutron instruments at a high intense neutron source is required to monitor high-intensity neutron beams. We have studied and prototyped a neutron monitor with nitrogen gas as neutron detection gas. In this study, we conducted a performance experiment of the nitrogen neutron monitor at NOBORU, a neutron instrument at the Materials and Life Science Experimental Facility of the J-PARC center. At the same time, measurements with other neutron monitors were done for comparison. In this presentation, we will explain the development status of the nitrogen neutron monitor and the results of the performance experiment.
300 K; o-xylene, m-xylene and p-xyleneHarada, Masahide; Abe, Yutaka*; Teshigawara, Makoto; Oi, Motoki; Ikeda, Yujiro*; Oikawa, Kenichi; Kawamura, Seiko; Inamura, Yasuhiro
no journal, ,
Hydrogenous materials are mainly applied as a moderator material used in high-intense and small neutron sources because of good moderating characterization for neutrons. Scattering data including total cross sections of cold-thermal neutrons are important to characterize moderators. However, as some measurements are old, we have been continuously and systematically measuring the cross sections of hydrogenous materials since 2018 for a new neutron source development. In this presentation, the measurements of o-xylene, m-xylene and p-xylene carried out in 2020 and 2021 will be presented as a hydrogenous material. The measurements were performed at NOBORU and AMATERAS in MLF of J-PARC. The total cross sections were measured at NOBORU, and the scattering cross sections were measured at AMATERAS. The sample temperatures were 20, 100, 200, 300 K and temperatures near the melting point. The sample was contained in an aluminum cell. The time-of-flight method was used to measure the energy-dependent transmission of the sample. The scattering data was converted to the scattering cross section by a multiple energy chopping. Details will be reported on the day.
Harada, Masahide; Abe, Yutaka*; Teshigawara, Makoto; Oi, Motoki; Ikeda, Yujiro; Oikawa, Kenichi; Nakajima, Kenji; Kawamura, Seiko
no journal, ,
By using neutron instruments, NOBORU and AMATERAS, in J-PARC spallation neutron source, we started to measure temperature dependent total and scattering cross section data of hydrogenous material ranging in thermal and cold neutron region. The cross section data of light water and ethanol were measured.
300 K; Methanol, benzene and tolueneHarada, Masahide; Abe, Yutaka*; Teshigawara, Makoto; Oi, Motoki; Ikeda, Yujiro*; Oikawa, Kenichi; Kawamura, Seiko; Inamura, Yasuhiro
no journal, ,
no abstracts in English
Yamamoto, Kazuyoshi; Xu, P. G.; Oikawa, Kenichi; Harada, Masahide; Inamura, Yasuhiro; Nakamura, Mitsutaka; Kodama, Katsuaki
no journal, ,
TOF neutron diffractometers typically use 
t
(time between neutron detection and target collision) as flight time. However, this is inaccurate due to moderator thermalization time after initial neutron slowing. We developed a patent-filed correction method to obtain a more accurate flight time. This involves pre-calculating the moderator's time response using neutron transport calculations and subtracting a delay time from t for each event. We validated this using data from J-PARC MLF-BL10 (NOBORU) and Rietveld analysis. Results show the correction reduces the coefficient of the quadratic term in the calibration equation (as determined by Rietveld analysis), improving linearity. Originally designed for small-scale sources, this method can be applied to larger facilities, contributing to the overall accuracy of TOF neutron diffraction, and this correction allows for more accurate measurements.