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JAEA Reports

Conceptual study of J-PARC Proton Beam Irradiation Facility

Meigo, Shinichiro; Iwamoto, Hiroki; Sugihara, Kenta*; Hirano, Yukinori*; Tsutsumi, Kazuyoshi*; Saito, Shigeru; Maekawa, Fujio

JAEA-Technology 2024-026, 123 Pages, 2025/03

JAEA-Technology-2024-026.pdf:14.22MB

Based on the design of the ADS Target Test Facility (TEF-T) at the J-PARC Transmutation Experimental Facility, a conceptual study was conducted on the J-PARC proton beam irradiation facility. This research was carried out based on the recommendations of the Nuclear Transmutation Technology Evaluation Task Force of the MEXT. The recommendations state that it is desirable to consider facility specifications that can make the most of the benefits of using the existing J-PARC proton accelerator while also solving the engineering issues of the ADS. We considered facilities that could respond to a variety of needs while reducing the facilities that were not needed in the TEF-T design. In order to clarify these diverse needs, we investigated the usage status of representative accelerator facilities around the world. As a result, it became clear that the main purposes of these facilities were (1) Material irradiation, (2) Soft error testing of semiconductor devices using spallation neutrons, (3) Production of RI for medical use, and (4) Proton beam use, and we investigated the facilities necessary for these purposes. In considering the facility concept, we assumed a user community in 2022 and reflected user opinions in the facility design. This report summarizes the results of the conceptual study of the proton irradiation facility, various needs and responses to them, the roadmap for facility construction, and future issues.

Journal Articles

J-PARC proton beam irradiation facility plan

Meigo, Shinichiro

Kasokuki, 21(4), p.333 - 344, 2025/01

For the study of material damage under the beam irradiation circumstance of accelerator-driven systems (ADS), the JAEA had planned to construct a TEF-T using J-PARC Linac 400-MeV proton beams and the LBE spallation target. The task force for evaluating partitioning and transmutation technology in the MEXT recommended that the facility be considered to maximize the advantages of using Linac to meet users' various needs. The proton irradiation facility, a successor of TEF-T, is planned to be constructed for 1) Material irradiation examinations, 2) Semiconductor soft-error examinations using spallation neutrons, 3) Medical RI production, and 4) Proton beam applications for space use. A user community was established in 2022 to incorporate user input as a more attractive facility. In this paper, the present design status of the facility is described.

Journal Articles

Measurement of the spallation neutron spectrum by unfolding at 180$$^{circ}$$ from 3-GeV protons and $$^{nat}$$Hg with the $$^{209}$$Bi(n,xn) reactions

Sugihara, Kenta*; Meigo, Shinichiro; Iwamoto, Hiroki; Maekawa, Fujio

JAEA-Conf 2024-002, p.162 - 167, 2024/11

A neutron energy spectrum is important for shielding design at an Accelerator-Driven System facility (1.5-GeV p + Lead Bismuth Eutectic). A similar spectrum can be obtained at J-PARC (3-GeV proton + $$^{nat}$$Hg). To check the validity of the unfolding, the unfolding with the $$^{209}$$Bi(n,xn) reactions and the response functions (JENDL/HE-2007 and TALYS) was applied. In our poster, we present the derivation of the spectrum and comparison with the spectrum with a Time-of-Flight technique.

Journal Articles

SiC sensor wire test by heavy ion beam irradiation, 2

Meigo, Shinichiro; Yamaguchi, Yuji

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.853 - 858, 2024/10

no abstracts in English

Journal Articles

Design and beam dynamics studies of a chopper for the JAEA-ADS LEBT

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

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.205 - 209, 2024/10

The Japan Atomic Energy Agency (JAEA) designs a 30-MW CW proton linear accelerator (linac) as a key component for the accelerator-driven subcritical system (ADS) project, aimed at nuclear waste management. The low energy beam transport (LEBT) in JAEA-ADS uses charge neutralization to minimize space-charge effects, which are the primary cause of beam loss in high-power accelerators. During commissioning and power ramp-up, precise control of the duty cycle is required for safety and machine protection; thus, a chopper system will be installed to manage the beam power. The chopper is located at the LEBT, to facilitate the disposal of the excess beam power, but its operation will affect the charge neutralization producing beam transients that could lead to beam loss. To shed light on this, we created a beam optics model for the chopper using an analytic approach to determine the required characteristics like voltage and dimensions, which was confirmed through TraceWin simulations. Subsequently, we analyzed the chopper's impact on space-charge compensation to evaluate the beam transients in the LEBT. This study reports the design of the chopper and its effects on beam performance for the JAEA-ADS LEBT.

Journal Articles

Proton beam utilization for space development equipment at J-PARC

Meigo, Shinichiro; Yamaguchi, Yuji; Iwamoto, Hiroki

Proceedings of 21st Annual Meeting of Particle Accelerator Society of Japan (Internet), p.32 - 37, 2024/10

no abstracts in English

Journal Articles

Automatic retuning of superconducting linacs using LightWin

Pla$c{c}$ais, A.*; Bouly, F.*; Froidefond, E.*; Lagniel, J.-M.*; Normand, G.*; Orduz, A. K.*; Yee-Rendon, B.; De Keukeleere, L.*; Van De Walle, J.*

Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.563 - 568, 2024/10

Reliability is an important feature for high power particle accelerators. This is particularly true for Accelerator-Driven Systems (ADS), for that every beam interruption can strongly affect the availability of the nuclear reactor. Many of these outages come from the loss of accelerating cavities or of their associated systems. Cavity failures can be compensated for by retuning other cavities of the linac. Finding the ideal compensation settings is however a difficult challenge that involves beam dynamics and multi-objective optimisation, and which raises very different issues according to the linac under study. For instance in the SPIRAL2 linac, a lot of cavities are mobilized for the compensation and the search space has a very high number of dimensions. Plus, it has quite low margins on the longitudinal acceptance. Linacs for ADS (such as the Japan Atomic Energy Agency ADS or MYRRHA) have a specific fault-tolerance design which facilitate the optimisation, but cavities have to be retuned in a few seconds. Hence we developed LightWin, a tool to automatically and systematically find compensation settings for every cavity failure of any given linac. In this study, we will present LightWin latest developments as well as the compensation strategies that we developed for SPIRAL2 and ADS linacs, both from a beam dynamics and a mathematical point of view.

Journal Articles

Progress of the spoke cavity prototyping for the JAEA-ADS linac

Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*

Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.496 - 498, 2024/10

Journal Articles

The LINACs simulation framework

Yee-Rendon, B.; Jameson, R. A.*; Okamura, Masahiro*; Li, C.*; Jiang, P.*; Maus, J. M.*

Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.492 - 495, 2024/10

LINACs is a simulation framework for designing optics and beam dynamics of charged particles in particle accelerators. LINACs is an open-source software that enables the user complete control over all design and simulation parameters of RFQs. This includes beam-driven design, fully 3D simulation using precise quadrupolar symmetry, and rigorous Poisson solution for external and space charge fields. The code can handle simultaneous particle beams with analytical input distributions and allows input beam scans. The software offers a relatively short running time and provides extensive analysis techniques. This work provides a historical overview of the code, presents results from RFQ models, and discusses future developments.

Journal Articles

Beam transient studies for the JAEA-ADS LEBT

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

Proceedings of 32nd Linear Accelerator Conference (LINAC 2024) (Internet), p.488 - 491, 2024/10

The Japan Atomic Energy Agency (JAEA) is designing a 30-MW CW proton linear accelerator (linac) for nuclear waste transmutation. Space-charge is the primary challenge in achieving low losses and high beam quality for high-power accelerators, especially at low energy levels where space-charge forces are greater. To counteract the space-charge effects, the low-energy beam transport (LEBT) uses a magnetostatic design to enable the neutralization of the beam charge, the so-called space charge compensation. The neutralization is an accumulation process that reaches a charge balance between the main beam and the opposite ionized particles. However, this equilibrium is destroyed by the chopper system used during beam ramping. During those transient regimes, the beam optics conditions are not optimal for the beam, producing considerable degradation that can end in serious damage to the accelerator. Thus, analysis of beam behavior at these periods is essential to develop a robust design and an efficient operation of the JAEA-ADS linac. This study presents the beam dynamics of neutralization build-up and chopper operation for the JAEA-ADS LEBT.

JAEA Reports

Conceptual study of Post Irradiation Examination (PIE) Facility at J-PARC

Saito, Shigeru; Meigo, Shinichiro; Makimura, Shunsuke*; Hirano, Yukinori*; Tsutsumi, Kazuyoshi*; Maekawa, Fujio

JAEA-Technology 2023-025, 48 Pages, 2024/03

JAEA-Technology-2023-025.pdf:3.11MB

JAEA has been developing Accelerator-Driven Systems (ADS) for research and development of nuclear transmutation using accelerators in order to reduce the volume and hazardousness of high-level radioactive waste generated by nuclear power plants. In order to prepare the material irradiation database necessary for the design of ADS and to study the irradiation effects in Lead-Bismuth Eutectic (LBE) alloys, a proton irradiation facility is under consideration at J-PARC. In this proton irradiation facility, 250 kW proton beams will be injected into the LBE spallation target, and irradiation tests under LBE flow will be performed for candidate structural materials for ADS. Furthermore, semiconductor soft-error tests, medical RI production, and proton beam applications will be performed. Among these, Post Irradiation Examination (PIE) of irradiated samples and RI separation and purification will be carried out in the PIE facility to be constructed near the proton irradiation facility. In this PIE facility, PIE of the equipment and samples irradiated in other facilities in J-PARC will also be performed. This report describes the conceptual study of the PIE facility, including the items to be tested, the test flow, the facilities, the test equipment, etc., and the proposed layout of the facility.

Journal Articles

Fabrication progress of the prototype spoke cavity for the JAEA-ADS linac

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)

Journal Articles

Design of the Low energy beam transport line for the JAEA-ADS linac

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

Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.545 - 549, 2023/11

The Japan Atomic Energy Agency (JAEA) is proposing a 30-MW proton linear accelerator (linac) for the application of accelerator-driven subcritical system (ADS) technology to achieve nuclear waste transmutation. A major challenge for the JAEA-ADS linac is the efficient transport of a 35 keV proton beam from the ion source to the radio-frequency quadrupole. In order to achieve this goal, we have optimized a magnetostatic low energy beam transport (LEBT) consisting of two solenoids to reduce the transmission of high-charge ions generated by the source and minimize the growth of proton emittance, while taking into account various space-charge compensation scenarios. In this report, we present the optical design and discuss the multiparticle tracking results of the JAEA-ADS LEBT.

Journal Articles

Development of a tool for cavity failure compensation in superconducting linacs; Progress and comparative study

Pla$c{c}$ais, A.*; Bouly, F.*; Yee-Rendon, B.

Proceedings of 14th International Particle Accelerator Conference (IPAC 23) (Internet), p.4097 - 4100, 2023/09

Reliability in high power hadron accelerators is a major issue, particularly for Accelerator Driven Systems (ADS). For example, the Japan Atomic Energy Agency (JAEA) ADS maximum frequency of beam trips longer than 5 min was set to 42 per year. A significant number of breakdowns are caused by the failure of accelerating cavities or by their associated systems. Hence, we studied how these can be effectively reduced. To this end, we developed the numerical tool LightWin that aims to determine the compensation settings for any superconducting (SC) linac automatically and systematically. This tool has been successfully used for the MYRRHA SC linac. In this work, we applied LightWin to compensate for several failure scenarios involving the last section of the JAEA ADS linac and compared the associated retuned settings and beam performance to those found in a previous study with TraceWin.

Journal Articles

Measurement of displacement cross-sections of Nb irradiated by protons with kinetic energy range between 0.4 and 3 GeV

Meigo, Shinichiro; Nakano, Keita*; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*

EPJ Web of Conferences, 284, p.05001_1 - 05001_4, 2023/05

 Times Cited Count:1 Percentile:68.83(Nuclear Science & Technology)

In high-intensity proton accelerator facilities such as Accelerator Driven System (ADS) and the spallation neutron source, it is crucial to evaluate the damage of beam-interception materials and accelerator components, such as a magnet coil. The displacement per atom (dpa) is used as a damage index, which is derived by integrating the particle flux and the displacement cross section based on the NRT model. Although the dpa is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. To obtain the data for superconducting materials for high-intensity accelerators and magnets, the displacement cross section of Nb for proton irradiation with a kinetic energy range between 0.4 and 3 GeV was measured. For sustaining damage in the sample, the Nb sample was cooled at a cryogenic temperature ($$sim$$8 K), where the recombination of Frenkel pairs due to thermal motion was well suppressed with maintaining the normal conductivity to maintain Matthiessen's rule. The displacement cross section of Nb was calculated using the PHITS code, and was compared with the present experimental results. It was found that the widely utilized NRT model overestimates the cross section by a factor of 2, as suggested by the previous works. It was also found that the calculation with a recently proposed athermal recombination corrected (arc) model based on Molecular Dynamics (MD) shows good agreement with the present data.

Journal Articles

Nuclide production cross sections in proton-induced reactions on Bi at GeV energies

Iwamoto, Hiroki; Nakano, Keita*; Meigo, Shinichiro; Takeshita, Hayato; Maekawa, Fujio

EPJ Web of Conferences, 284, p.01033_1 - 01033_4, 2023/05

 Times Cited Count:1 Percentile:68.83(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Measurement of double-differential neutron yields for iron, lead, and bismuth induced by 107-MeV protons for research and development of accelerator-driven systems

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta*; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

EPJ Web of Conferences, 284, p.01023_1 - 01023_4, 2023/05

 Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)

For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron, lead, and bismuth have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics. The measured TTNYs and DDXs were compared with calculations by the Monte Carlo transport code PHITS with its default physics model of INCL version 4.6 combined with GEM and those with the JENDL-4.0/HE nuclear data library.

Journal Articles

Design and optimization of a proton source extraction system for the JAEA-ADS linac

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

Proceedings of 14th International Particle Accelerator Conference (IPAC 23) (Internet), p.1591 - 1593, 2023/05

The Japan Atomic Energy Agency (JAEA) is designing a 30 MW continuous wave (cw) superconducting proton linear accelerator (linac) for the Accelerator Driven System (ADS) proposal. The JAEA-ADS linacs ion source must provide a proton beam over 20 mA with an energy of 35 keV and a normalized rms emittance of less than 0.1 $$pi$$ mm mrad. As the extraction system determines the beam properties and quality, systematic optimizations on the geometry and input values of the extraction system design were conducted using the AXCEL-INP 2-D simulation program to satisfy the goal requirements. This work describes the extraction system design and reports the beam dynamics results of the first study for the proton source of the JAEA-ADS linac.

Journal Articles

Measurement of 107-MeV proton-induced double-differential thick target neutron yields for Fe, Pb, and Bi using a fixed-field alternating gradient accelerator at Kyoto University

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

Journal of Nuclear Science and Technology, 60(4), p.435 - 449, 2023/04

 Times Cited Count:4 Percentile:51.78(Nuclear Science & Technology)

Double-differential thick target neutron yields (TTNYs) for Fe, Pb, and Bi targets induced by 107-MeV protons were measured using the fixed-field alternating gradient accelerator at Kyoto University for research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research at the Kyoto University Critical Assembly (KUCA). Note that TTNYs were obtained with the time-of-flight method using a neutron detector system comprising eight neutron detectors; each detector has a small NE213 liquid organic scintillator and photomultiplier tube. The TTNYs obtained were compared with calculation results using Monte Carlo-based spallation models (i.e., INCL4.6/GEM, Bertini/GEM, JQMD/GEM, and JQMD/SMM/GEM) and the evaluated high-energy nuclear data library, i.e., JENDL-4.0/HE, implemented in the particle and heavy iontransport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of 5$$^{circ}$$. Comparing the energy- and angle-integrated spallation neutron yields at energies of $$le$$20 MeV estimated using the measured TTNYs and the PHITS indicated that INCL4.6/GEM would be suitable for the Monte Carlo transport simulation of ADS reactor physics experiments at the KUCA.

266 (Records 1-20 displayed on this page)