Plasma and Fusion Research

Volume 21, 1404031 (2026)

Regular Articles

Robustness of Key Parameters in Implosion of Multilayer Fuel Targets Against Change in Heavy-Ion Beam Parameters for Heavy-Ion Inertial Fusion
Naoto WATANABE1), Kazumasa TAKAHASHI2), Toru SASAKI3), Takashi KIKUCHI4)
1)
National Institute of Technology, Nagano College, Department of Engineering, Mechanics and Robotics Course, 716 Tokuma, Nagano, Nagano 381-8550, Japan
2)
Nagaoka University of Technology, Department of Electrical, Electronics and Information Engineering, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
3)
Nagaoka University of Technology, Department of Science of Technology Innovation, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
4)
Nagaoka University of Technology, Department of Nuclear Technology, 1603-1 Kamitomioka Nagaoka, Niigata 940-2188, Japan
(Received 14 October 2025 / Accepted 24 February 2026 / Published 18 June 2026)

Abstract

This study investigated the effects of heavy-ion beam (HIB) pulse waveform and irradiation time on the implosion process of a multilayer fuel target designed for heavy-ion inertial fusion (HIF). Achieving high beam intensity, beam quality, and precise timing synchronization is challenging owing to the space charge effect. Multilayer fuel targets with low-density foam layers may alleviate these beam condition requirements and help achieve robust, uniform implosion. Using a 1-D spherical coordinate hydrodynamic model, this study evaluated implosion dynamics and variation using the coefficient of variation. Results showed that multilayer targets offer enhanced robustness against beam irradiation time variations compared to conventional designs. The Pb pusher configuration consistently demonstrated superior stability, attributed to the high density and atomic number of Lead that influences transport and hydrodynamics. The foam layer also plays a crucial role in mitigating the adverse effects of timing fluctuations. These findings suggest that multilayer fuel targets, particularly with a Pb pusher, provide a compelling advantage for practical applications by offering improved robustness and simplifying parameter optimization procedures compared to conventional HIF targets.

Keywords

heavy-ion inertial fusion, heavy ion beam, robustness, implosion, simulation, fluid dynamics

DOI: 10.1585/pfr.21.1404031

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References

  • [1] J. Lindl et al., Phys. Plasmas 11, 339 (2004).
  • [2] T. Peter and J. Meyer-ter-Vehn, Phys. Rev. A 43, 1998 (1991).
  • [3] M. Reiser, Theory and design of charged particle beams (Wiley, 2008).
  • [4] R.C. Kirkpatrick and R.E. Kidder, Nucl. Fusion 16, 697 (1976).
  • [5] T. Someya et al., Laser Part. Beams 24, 359 (2006).
  • [6] N. Watanabe et al., Plasma Fusion Res. 17, 2404086 (2022).
  • [7] S. Kawata et al., Matter Radiat. at Extremes. 1, 89 (2016).