Beam optics design of the superconducting region of the JAEA ADS

Yee-Rendon, B.; Kondo, Yasuhiro; Maekawa, Fujio; Meigo, Shinichiro; Tamura, Jun

Journal of Physics; Conference Series, 1350(1), p.012120_1 - 012120_5, 2019/12

https://iopscience.iop.org/article/10.1088/1742-6596/1350/1/012120

Design of the elliptical superconducting cavities for the JAEA ADS

Yee-Rendon, B.; Kondo, Yasuhiro; Maekawa, Fujio; Meigo, Shinichiro; Tamura, Jun

Journal of Physics; Conference Series, 1350(1), p.012198_1 - 012198_6, 2019/12

https://iopscience.iop.org/article/10.1088/1742-6596/1350/1/012198

Measurement of activation cross sections of aluminum for protons with energies between 0.4 GeV and 3.0 GeV at J-PARC

Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki

Progress in Nuclear Science and Technology (Internet), 6, p.171 - 174, 2019/01

https://doi.org/10.15669/pnst.6.171

Activation cross sections of various materials are strongly required for the improvement of the accuracy of nuclear design and the reduction of the construction costs for spallation neutron sources and transmutation systems. Activation cross sections have been measured in several facilities. However, they have low accuracy and precision. Especially, there are merely experimental data with 3 GeV protons which are used for spallation neutron source (MLF) in J-PARC, the experimental data is required for the improvement of the target materials. Thus, we measured cross sections of tungsten, gold, indium, and beryllium with 0.4 GeV to 3.0 GeV protons. Moreover, ones of aluminium that are set with materials were also measured for a variation of this experiment. It was found that more accurate data than current ones would be measured by using precise beam controls and highly accurate beam monitoring. We compared the experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by PHITS code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (GEM) being included in PHITS code. We found that the calculations agreed with the experimental data by upgrading PHITS code. The cross sections for the other materials have been analysed so far.

Proton-induced activation cross section measurement for aluminum with proton energy range from 0.4 to 3 GeV at J-PARC

Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki

Journal of Nuclear Science and Technology, 55(8), p.955 - 961, 2018/08

https://doi.org/10.1080/00223131.2018.1461694

We have started an experimental program to measure activation cross sections systematically in the proton-induced spallation reaction in structural materials commonly used in high-intensity proton accelerator-based facilities, such as Japan Proton Accelerator Research Complex (J-PARC). As the first step of the program, aluminum (Al) was chosen to verify the adequacy of the measurement technique implemented in a J-PARC proton beam environment because data of Al have been relatively well studied both by experimental measurement and simulation. Activation cross sections of Be, Na, and Na in Al were measured at proton energy points from 0.4, 1.3, 2.2 to 3.0 GeV, which could be delivered smoothly from the synchrotron. The validity of experimental data has been verified by introducing an effective proton numbers determination procedure. We compared the measured data with existing experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by the Particle and Heavy Ion Transport code System (PHITS) code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (generalized evaporation model) being implemented in the PHITS code. We found that the calculations agreed with the experimental data by an upgraded PHITS code.

Beam instruments for high power spallation neutron source and facility for ADS

Meigo, Shinichiro

Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.99 - 103, 2018/07

https://doi.org/10.18429/JACoW-HB2018-TUP1WE03

As the increase of beam power, beam instruments play an essential role in the Hadron accelerator facility. In J-PARC, the pitting erosion on the mercury target vessel for the spallation neutron source is one of a pivotal issue to operate with the high power of the beam operation. Since the erosion is proportional to the 4th power of the beam current density, the minimization of the peak current density is required. To achieve low current density, the beam-flattening system by nonlinear beam optics in J-PARC, by which the peak density was successfully reduced by 30% than the density with the conventional case optics. Since the ADS requires a very powerful accelerator with the beam power such as 30 MW, a robust beam profile monitor is required, especially for the observation of the beam status on the target continuously. A candidate material for the beam monitor was developed by using heavy-ion of Ar beam to give the damage efficiently.

The Measurements of neutron energy spectrum at 180 degrees with the mercury target at J-PARC

Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki

Journal of Physics; Conference Series, 1021(1), p.012017_1 - 012017_4, 2018/06

https://doi.org/10.1088/1742-6596/1021/1/012017

Spallation neutron at 180 degrees is of important for an evaluation of radiation protection for ADS (Accelerator-Driven System) and the nuclear physics. It was, however, quite difficult to measure it. We measured the energy spectrum of spallation neutron at 180 degrees at the proton transport beam line (3NBT) to MLF (Materials and Life Science Experimental Facility) on J-PARC by the NE213 liquid scintillator. The irradiated proton energy was 3 GeV, and the intensity was 110 protons above. The neutron energy was determined by Time-Of-Flight method with n-gamma discrimination. We also simulated the energy spectrum by using PHITS code and compared with measured spectrum. In this paper, the overview of the experiment and the results are described.

Shielding analysis of Transmutation Experimental Facility

Iwamoto, Hiroki; Matsuda, Hiroki; Meigo, Shinichiro

Journal of Physics; Conference Series, 1021(1), p.012049_1 - 012049_4, 2018/06

https://doi.org/10.1088/1742-6596/1021/1/012049

To promote research, development, and demonstration of elemental technologies for accelerator-driven systems (ADS), the Japan Atomic Energy Agency (JAEA) is planning to construct Transmutation Experimental Facility (TEF) at J-PARC. At ADS Target Test Facility (TEF-T), 250-kW H beams accelerated by the 400-MeVLINAC will be derived to a lead-bismuth eutectic (LBE) target for the material examinations aimed for the ADS. The TEF-T will operate as a spallation neutron source especially for research and development of semiconductor by using high-energy neutrons. For the license of this facility, the shielding design is important because unnecessary shield increase drastically the cost of construction. In this study, shielding analysis was carried out for whole structure of the TEF in detail toward the construction. To reduce the neutron flux and cost efficiently, an iron and an ordinary concrete will be employed as shield. The detailed structure for the shielding was determined by the PHITS code based on the intra-nuclear cascade with statistical decay model. It was found that the backward neutrons from the target are important to reduce the cost of the shielding so that we have plan to measure by using J-PARC accelerator. Shielding including the beam tunnel, hot-cell to maintain the LBE target, beam dumps for beam commissioning, and a neutron beam port for multipurpose utilization were also determined. This paper presents the results of the shielding analysis for these components and the shielding structure of the whole TEF.

Cross section measurement in J-PARC for neutronics of the ADS

Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Hiroki

Proceedings of 13th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '17) (Internet), p.396 - 402, 2018/05

no abstracts in English

Beam extraction by the laser charge exchange method using the 3-MeV linac in J-PARC

Takei, Hayanori; Hirano, Koichiro; Meigo, Shinichiro; Tsutsumi, Kazuyoshi*

Proceedings of 6th International Beam Instrumentation Conference (IBIC 2017) (Internet), p.435 - 439, 2018/03

https://doi.org/10.18429/JACoW-IBIC2017-WEPCF08

The Japan Proton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV negative proton (H) beam will be delivered from the J-PARC linac. Since the TEF-P requires a stable proton beam with a power of less than 10 W, a stable and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250 kW. To fulfil this requirement, the Laser Charge Exchange (LCE) method has been developed. To demonstrate the charge exchange of the H, a preliminary LCE experiment was conducted using a linac with energy of 3 MeV in J-PARC. As a result of the experiment, a charge-exchanged H beam with a power of about 8 W equivalent and an accuracy of about 2% was obtained under the J-PARC linac beam condition.

Assessment of lead-bismuth-eutectic leak at ADS Target Test Facility in Transmutation Experimental Facility of J-PARC

Iwamoto, Hiroki; Maekawa, Fujio; Matsuda, Hiroki; Meigo, Shinichiro

JAEA-Technology 2017-029, 39 Pages, 2018/01

JAEA-Technology-2017-029.pdf:2.68MB

Under an assumption that an incident of lead-bismuth eutectic (LBE) leak from an LBE circulation system occurred during a 250-kW beam operation, an estimation of radiation dose at the site boundary for the ADS Target Test Facility (TEF-T) in Transmutation Experimental Facility (TEF) of J-PARC was conducted using various conservative assumptions. As a result, the radiation dose at the site boundary was estimated to be about 660 Sv, which were dominated by mercury, noble gas, and iodine produced as spallation products from the LBE. Even though the incident scenario was made conservatively, it was shown that the estimated total dose was lower than the annual radiation dose due to natural sources, and the TEF-T has sufficient safety margin for the leak of radioactivity.