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-Ps) in fluorinated polymers and silica glassKobayashi, Yoshinori*; Sato, Kiminori*; Yamawaki, Masato*; Michishio, Koji*; Oka, Toshitaka; Washio, Masakazu*
Journal of Physics; Conference Series, 3029, p.012001_1 - 012001_7, 2025/06
Mo/
Tc radioisotope separation by modified extraction methodPratama, C.*; Fujita, Yoshitaka; Saptiama, I.*; Marlina, M.*; Triyatna, F.*; Ilhami, A.*; Maria, C. P.*; Tsuchiya, Kunihiko; Teguh, A.*; Prasetyo, I.*
Journal of Physics; Conference Series, 2828, p.012025_1 - 012025_12, 2024/10
no abstracts in English
Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Soyama, Kazuhiko; Koyama, Tomio*; et al.
Journal of Physics; Conference Series, 2776, p.012009_1 - 012009_9, 2024/06
ion sourceUeno, Akira
Journal of Physics; Conference Series, 2743(1), p.012001_1 - 012001_8, 2024/05
Times Cited Count：1 Percentile：89.11(Physics, Particles & Fields)On 2020, the 8 hours operation of the J-PARC cesiated RF-driven H ion source (IS) with a 69.9 keV 120 mA beam was reported. Many times and large amount of Cs and H
O injections were required. The very high plasma etectrode temperature (T
) of 245
C suggests a novel cesiation surviving against high T and plasma bombardments. A procedure based upon a hypothesis of the HO (chemically bound with Mo) mediated cesiation was examined. The innovative cesiation derived a 76.5 keV 145 mA beam stably with the small beam fluctuation and transverse emittances suitable for RFQs of high energy LINACs. Furthermore, the beam intensity for the J-PARC IS operation energy of 52.5 keV was increased from 72 mA to 83 mA which should contribute for the stable J-PARC LINAC 60 mA operation in near future.
Shibata, Takanori*; Shinto, Katsuhiro; Nakano, Haruhisa*; Hoshino, Kazuo*; Miyamoto, Kenji*; Okoshi, Kiyonori; Nammo, Kesao*; Ikegami, Kiyoshi*; Kawai, Isao*; Oguri, Hidetomo; et al.
Journal of Physics; Conference Series, 2743, p.012007_1 - 012007_5, 2024/05
Times Cited Count：0 Percentile：0.00(Physics, Particles & Fields)Oscillation of the negative hydrogen ion (H
) beam phase space in Radio Frequency (RF) ion source is investigated by a simple 3D Particle-In-Cell (PIC) model which takes into account the transport processes of electron, proton and H in the extraction region. The calculation domain is in vicinity of the single beam aperture in J-PARC ion source configuration. In order to understand relation between the plasma density oscillation and the extracted H beam characteristics, the input electron and proton fluxes from the driver region are varied parametrically with the 1st and the 2nd harmonics of the J-PARC RF frequency (2 or 4 MHz). The numerical results give an idea to the main physical processes between the oscillations of the plasma parameters and the extracted H ion trajectories in the different RF phases. Countermeasures to reduce the oscillation mechanisms are also discussed in the presentation.
ion sourceShinto, Katsuhiro; Shibata, Takanori*; Okoshi, Kiyonori; Nammo, Kesao*; Kawai, Isao*; Ikegami, Kiyoshi*
Journal of Physics; Conference Series, 2743, p.012023_1 - 012023_5, 2024/05
Times Cited Count：0 Percentile：0.00(Physics, Particles & Fields)We have been conducting the test of a new J-PARC-made internal antenna for the J-PARC RF-driven cesiated H ion source. After the development of the first J-PARC-made antenna, the composition of the porcelain enamel coating of the antenna was changed because we were afraid of the outgassing of the impurities from the previous antenna coating. During the test of high-density plasma production by the new antenna, we monitored the outgassing characteristics of the new antenna by measuring mass spectrometry and optical spectrum analysis. It is confirmed that no remarkable impurities were emitted from the new antenna. We also carried out the H beam extraction and measured the H beam characteristics by using the new antenna. It is found that the emittances of the H beam extracted from the J-PARC RF-driven cesiated H ion source by using the new antenna were similar to those in the case by using the SNS-made antenna. To accelerate the endurance test of the new antenna, we applied the antenna for the high-density plasma production to the 5% duty factor (1 ms pulse width with 50 Hz repetition rate) with the 2 MHz RF input power of approximately 60 kW, whose values were much higher than those in the J-PARC nominal operation; 0.8 ms pulse width with 25 Hz repetition rate (the duty factor of 2%) with the RF input power of approximately 30 kW. This presentation shows the results of the characteristics of the new J-PARC-made antenna and discusses the feasibility of the new antenna for use in the J-PARC accelerator operation.
ion beam extracted from an RF wave excited ion source plasmaWada, Motoi*; Shibata, Takanori*; Shinto, Katsuhiro
Journal of Physics; Conference Series, 2743, p.012031_1 - 012031_5, 2024/05
Times Cited Count：0 Percentile：0.00(Physics, Particles & Fields)An internal antenna type RF driven negative hydrogen (H) ion source supplies beams to the J-PARC accelerator facility. The H ion beam current exhibits high stability, while it fluctuates with less than 5% amplitude of the DC current when a Faraday cup measures the current extracted from the source mounted on a test stand. Two frequencies are identified as the main oscillation components, 2 MHz and 4 MHz which are the driving RF frequency and the second harmonics, respectively. The amplitude levels of these components appear larger as parts of the beam directing specific angles passing through a slit are detected. A possible reason for observing a small amplitude oscillation in the total beam intensity is the averaged phase-shift of the local beam depending upon the position of the H ion production and the succeeding trajectory reaching the Faraday cup. To confirm if the phase-shift is the main reason for diminishing the oscillation amplitude for the total beam, the phase-shift between the 2 MHz and 4 MHz components were measured for beams passing through a 0.1 mm slit coupled to a Faraday cup having a 0.1 mm entrance slit. The result indicated the phase-shift changed substantially depending upon the position, but no simple model can explain the measured spatial distribution of the phase-shift. Further attempts will be made to clarify the beam dynamics relevant to the H ion beam transport including the measurements of the beam current phase-shift with respect to the RF antenna current, and the time evolution of Balmer-
light emission.
Yamada, Ippei; Chimura, Motoki; Kamiya, Junichiro; Kinsho, Michikazu
Journal of Physics; Conference Series, 2687(7), p.072018_1 - 072018_6, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)no abstracts in English
Okita, Hidefumi; Tamura, Fumihiko; Yamamoto, Masanobu; Nomura, Masahiro; Shimada, Taihei; Saha, P. K.; Yoshii, Masahito*; Omori, Chihiro*; Sugiyama, Yasuyuki*; Hasegawa, Katsushi*; et al.
Journal of Physics; Conference Series, 2687(7), p.072005_1 - 072005_7, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)Longitudinal phase space tomography is an effective measurement tool for acquiring the longitudinal phase space distribution. For the J-PARC synchrotrons, tomography, which can take into account the beam dynamics such as longitudinal space charge effect and nonlinearity, is desired, as the beam power increases. In this study, for the J-PARC synchrotron, the CERN's tomography, which employs the hybrid algorithm that can consider the beam dynamics for reconstruction, is introduced and benchmarked. The benchmark results show that the CERN's tomography has the ability to measure the longitudinal phase space distribution accurately, in the high-power beam operation at the J-PARC synchrotrons.
Takahashi, Hiroki; Saha, P. K.; Yoshimoto, Masahiro; Sawabe, Yuki*
Journal of Physics; Conference Series, 2687(7), p.072019_1 - 072019_5, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)In J-PARC 3 GeV Rapid Cycling Synchrotron, the synchronized data system using reflective memory has been constructed. In order to support the requirement of using larger size data in high intensity beam operation in the future, a new synchronized data generation method has been proposed. The new method implements in the measurement system the functions performed by the high-level computer in the current system, thereby realizing synchronized data generation using data transfer via LAN. In this study, we have constructed a test bench for the new synchronized data system that implements the proposed method and verified its performance. This result leads to the development of the new synchronized data system based on data transfer via LAN. In this paper, we describe the outline of the new synchronized data generation method and the results of performance tests.
Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Journal of Physics; Conference Series, 2687(5), p.052008_1 - 052008_6, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)Kitamura, Ryo; Hayashi, Naoki; Hirano, Koichiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Morishita, Takatoshi; Nemoto, Yasuo*
Journal of Physics; Conference Series, 2687(7), p.072006_1 - 072006_6, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)The mitigation of heat loading is one of the important issues for beam instrumentation to measure the high-power proton beam. Recently, the highly-oriented pyrolytic graphite (HOPG) material was used for the target probe of the bunch-shape monitor at the front-end in the Japan Proton Accelerator Research Complex (J-PARC). Since the thermal conductivity of the HOPG is high, it is suitable to measure the beam profile under the condition of high heat loading. As an application of the HOPG, for example, the thin HOPG may be used as a substitutive material of the target wire for the transverse profile monitor such as the wire scanner monitor. The possibility of the HOPG target for the beam profile monitor is discussed from some results of the test experiment using the 3-MeV negative hydrogen ion beam at the test stand.
Takayanagi, Tomohiro; Ono, Ayato; Sugita, Moe; Yamamoto, Kazami; Oguri, Hidetomo; Kinsho, Michikazu; Horino, Koki*; Ueno, Tomoaki*; Oda, Kodai*; Tokuchi, Akira*; et al.
Journal of Physics; Conference Series, 2687(8), p.082021_1 - 082021_7, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)A new kicker power supply using SiC-MOSFETs is under development at J-PARC. The base circuit uses an induction voltage superposition circuit of the LTD method, and the semiconductor module circuit consists of a radial symmetry type that achieves low noise. The three main parts of an existing kicker power supply, the thyratron, PFN circuit, and end clipper, can be configured in a single module circuit. The power supply consists of a main circuit module board that forms a trapezoidal pulse and a correction circuit module board that compensates for droop of the flat section. The thirty-two main circuit module boards and twenty correction circuit module boards are connected in series in a hierarchical manner to achieve the waveform specifications required for J-PARC RCS kicker power supplies. In addition, an insulating cylinder for conductors has been developed that suppresses corona discharge and withstands continuous operation for long periods of time.
Saha, P. K.; Harada, Hiroyuki; Shobuda, Yoshihiro; Tamura, Fumihiko; Okita, Hidefumi; Okabe, Kota; Nakanoya, Takamitsu; Hatakeyama, Shuichiro; Moriya, Katsuhiro; Takayanagi, Tomohiro; et al.
Journal of Physics; Conference Series, 2687(5), p.052020_1 - 052020_7, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)Kurita, Keisuke; Iikura, Hiroshi; Tsuchikawa, Yusuke; Kai, Tetsuya; Shinohara, Takenao; Odaira, Naoya*; Ito, Daisuke*; Saito, Yasushi*; Matsubayashi, Masahito
Journal of Physics; Conference Series, 2605, p.012005_1 - 012005_6, 2023/10
The Japan Research Ractor-3 (JRR-3) is operation resumed on February 26, 2021, and the shared use was also restarted in July, 2021. With the resumption of JRR-3 operation, two imaging facilities called TNRF and CNRF have also resumed their utilization. In this presentation, we report the details of these two neutron facilities.
Ito, Daisuke*; Odaira, Naoya*; Ito, Kei*; Saito, Yasushi*; Kurita, Keisuke; Iikura, Hiroshi
Journal of Physics; Conference Series, 2605, p.012024_1 - 012024_6, 2023/10
Gas-liquid two-phase flow appears in many heat-exchanging devices. To understand the phenomena in such devices, the two-phase flow dynamics should be clarified. In this study, high-speed neutron imaging is applied to the measurements of two-phase flow dynamics, and the accuracy of the void fraction measurement is investigated.
Tsuchikawa, Yusuke; Kai, Tetsuya; Abe, Yuta; Oikawa, Kenichi; Parker, J. D.*; Shinohara, Takenao; Sato, Ikken
Journal of Physics; Conference Series, 2605, p.012022_1 - 012022_6, 2023/10
We developed a method to obtain the areal density distribution of boron, which has a large neutron cross section, by means of an energy resolved neutron imaging. Commonly in a measurement of elements with very high neutron sensitivity, the quantitative measurement becomes more difficult with the amount of element due to the neutron self-shielding effect. To avoid this effect, an energy-resolved method using known cross section data was attempted, and a quantitative imaging of such elements was demonstrated at the MLF of J-PARC. This presentation introduces a measurement of melted simulated-fuel assemblies obtained in the research of the Fukushima Daiichi Nuclear Power Plant after the severe accident. Energy-dependent neutron transmission rates of the samples were measured by a neutron imaging detector, and were analyzed to obtained the areal density of boron at each position.
Saito, Yasushi*; Ito, Daisuke*; Odaira, Naoya*; Kurita, Keisuke; Iikura, Hiroshi
Journal of Physics; Conference Series, 2605, p.012028_1 - 012028_6, 2023/10
To observe flow velocity distributions by Neutron Imaging, suitable tracer is necessary. The requirements are its density, its visibility, and its wettability (if applied to liquid metal). Gold cadmium tracers have been developed for the Pb-Bi two-phase flow, however, the visibility have not been verified depending on the particle size and the measurement system. As the candidates of tracer particles, Ag, Cd, Au-Cd, and Ag-Cd have been tested by varying its compositions and its diameters. Results show enough visibility if the particles size is larger than 1mm. In addition, Cd tracer particles were applied to the fluidized bed, where the bed materials are metallic particle made of stainless steel, with 1mm diameter. The diameter of Cd trace is about 1.5 mm. From the neutron imaging, the visibility of the tracers is enough to measure the velocity distributions in the fluidized bed.
Oikawa, Kenichi; Sato, Hirotaka*; Watanabe, Kenichi*; Su, Y. H.; Shinohara, Takenao; Kai, Tetsuya; Kiyanagi, Yoshiaki*; Hasemi, Hiroyuki
Journal of Physics; Conference Series, 2605, p.012013_1 - 012013_6, 2023/10
Chiu, I.-H.; Terada, Kentaro*; Osawa, Takahito; Park, C.*; Takeshita, Soshi*; Miyake, Yasuhiro*; Ninomiya, Kazuhiko*
Journal of Physics; Conference Series, 2462, p.012004_1 - 012004_6, 2023/03
Times Cited Count：1 Percentile：71.57(Physics, Applied)In the last decade, non-destructive elemental analysis using negative muon beams advanced significantly. This method can be used to determine the elemental composition of bulk materials without causing damage. In this study, we performed a negative muon irradiation experiment for a Northwest Africa 482 lunar meteorite (NWA482), which was installed in a stainless steel analysis chamber. The analysis chamber was filled with helium gas to suppress the background signals caused by air-scattering muons. The muonic X-rays from Al, Fe, Ca, Mg, Si, and O in the samples were detected using six high-purity germanium semiconductor detectors arranged around the analysis chamber. To correct the X-ray self-absorption effect of the samples, a Monte-Carlo simulation using Geant4 toolkit was used. Based on the quantitative analysis for muonic X-ray measurement with the correction application from the simulation, we successfully investigated the analytical sensitivity of each element in meteorites based on the NWA482 data.
