3D radiation-hydrodynamics simulations of octahedral spherical hohlraums

Ramis Rafael

doi:10.1063/5.0291101

Volume 11 Issue 2

Mar. 2026

Turn off MathJax

Article Contents

Article Navigation > Matter and Radiation at Extremes > 2026 > 11(2): 027601

Ramis Rafael. 3D radiation-hydrodynamics simulations of octahedral spherical hohlraums[J]. Matter and Radiation at Extremes, 2026, 11(2): 027601. doi: 10.1063/5.0291101

Citation:

Ramis Rafael. 3D radiation-hydrodynamics simulations of octahedral spherical hohlraums[J]. Matter and Radiation at Extremes, 2026, 11(2): 027601. doi: 10.1063/5.0291101

Ramis Rafael. 3D radiation-hydrodynamics simulations of octahedral spherical hohlraums[J]. Matter and Radiation at Extremes, 2026, 11(2): 027601. doi: 10.1063/5.0291101

Citation:

Ramis Rafael. 3D radiation-hydrodynamics simulations of octahedral spherical hohlraums[J]. Matter and Radiation at Extremes, 2026, 11(2): 027601. doi: 10.1063/5.0291101

PDF( 13238 KB)

3D radiation-hydrodynamics simulations of octahedral spherical hohlraums

doi: 10.1063/5.0291101

Ramis Rafael^{,
,}

E.T.S.I. Aeronáutica y del Espacio, Universidad Politécnica de Madrid, P. Cardenal Cisneros 3, E-28040 Madrid, Spain

More Information

Corresponding author: a)Author to whom correspondence should be addressed: rafael.ramis@upm.es
Received Date: 2025-07-15
Accepted Date: 2025-11-13

Available Online: 2026-03-01

Publish Date: 2026-03-01

Abstract

Abstract

Achieving uniform X-ray irradiation in indirect-drive inertial confinement fusion (ICF) is a key challenge for successful capsule implosion. Spherical hohlraums, particularly those with octahedral laser entrance holes (LEHs), are an alternative to the cylindrical hohlraums currently considered for ICF at NIF (USA) and LMJ (France). These spherical hohlraums are advantageous in terms of irradiation uniformity on the fusion capsule because, owing to their octahedral symmetry, low-order asymmetries cancel out intrinsically. However, they may be less favorable from an energetic point of view, primarily owing to radiation losses through their multiple LEHs. The net balance of these advantages and disadvantages is difficult to determine, because, unlike cylindrical hohlraums, they require fully 3D modeling. To address this, a new version of the MULTI-3D simulation code has been developed. MULTI-3D is a 3D radiation-hydrodynamics code with arbitrary Langrangian–Eulerian (ALE) hydrodynamics, multigroup S_N radiation transport, and ray-tracing laser deposition. Using this tool, several aspects of the behavior of spherical hohlraums have been analyzed, with special attention to phenomena inaccessible to 2D modeling. In these targets, laser beams strike the inner walls at very oblique angles, and the expansion of plasma significantly alters the locations where primary X rays are produced. Furthermore, the complex distribution of laser hot spots leads to mutual interactions, where plasma bubbles from one beam intersect the path of another. The laser-to-X-ray energy conversion efficiency has been analyzed as a function of key parameters. The symmetry on the capsule has also been evaluated, revealing nonuniformities of less than 1%.

The author has no conflicts to disclose.
Conflict of Interest
Author Contributions
Rafael Ramis: Conceptualization (equal).
The data that support the findings of this study are available from the corresponding author upon reasonable request.

FullText(HTML)

References(34)

References

[1]	J. H. Nuckolls, L. Wood, A. Thiessen, and G. B. Zimmermann, “Laser compression of matter to super-high densities: Thermonuclear (CTR) applications,” Nature 239, 139–142 (1972).10.1038/239139a0.
[2]	S. Atzeni and J. Meyer-ter-Vehn, The Physics of Inertial Fusion (Oxford Science Publications, Oxford, 2004), pp. 1–480.
[3]	J. Lindl, “Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain,” Phys. Plasmas 2, 3933 (1995).10.1063/1.871025
[4]	S. W. Haan, J. D. Lindl, D. A. Callahan, D. S. Clark, J. D. Salmonson et al., “Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility,” Phys. Plasmas 18, 051001 (2011).10.1063/1.3592169
[5]	H. Abu-Shawareb, R. Acree, P. Adams, J. Adams, B. Addis et al., “Achievement of target gain larger than unity in an inertial fusion experiment,” Phys. Rev. Lett. 132, 065102 (2024).10.1103/physrevlett.132.065102
[6]	A. L. Kritcher, D. J. Schlossberg, C. R. Weber, C. V. Young, O. A. Hurricane et al., “Design of first experiment to achieve fusion target gain > 1,” Phys. Plasmas 31, 070502 (2024).10.1063/5.0210904
[7]	K. Lan, J. Liu, D. Lai, W. Zheng, and X.-T. He, “High flux symmetry of the spherical hohlraum with octahedral 6LEHs at the hohlraum-to-capsule radius ratio of 5.14,” Phys. Plasmas 21, 010704 (2014).10.1063/1.4863435
[8]	K. Lan, X.-T. He, J. Liu, W. Zheng, and D. Lai, “Octahedral spherical hohlraum and its laser arrangement for inertial fusion,” Phys. Plasmas 21, 052704 (2014).10.1063/1.4878835
[9]	K. Lan and W. Zheng, “Novel spherical hohlraum with cylindrical laser entrance holes and shields,” Phys. Plasmas 21, 090704 (2014).10.1063/1.4895503
[10]	K. Lan, J. Liu, Z. Li, X. Xie, W. Huo et al., “Progress in octahedral spherical hohlraum study,” Matter Radiat. Extremes 1, 8–27 (2016).10.1016/j.mre.2016.01.003
[11]	K. Lan, “Dream fusion in octahedral spherical hohlraum,” Matter Radiat. Extremes 7, 055701 (2022).10.1063/5.0103362
[12]	R. K. Follett, J. G. Shaw, J. F. Myatt, V. N. Goncharov, D. H. Edgell et al., “Ray-based modeling of cross-beam energy transfer at caustics,” Phys. Rev. E 98, 043202 (2018).10.1103/physreve.98.043202
[13]	K. Lan, Z. Li, X. Xie, Y.-H. Chen, C. Zheng et al., “Experimental demonstration of low laser-plasma instabilities in gas-filled spherical hohlraums at laser injection angle designed for ignition target,” Phys. Rev. E 95, 031202(R) (2017).10.1103/physreve.95.031202
[14]	R. Ramis, “Hydrodynamic analysis of laser-driven cylindrical implosions,” Phys. Plasmas 20, 082705 (2013).10.1063/1.4818801
[15]	R. Ramis, M. Temporal, B. Canaud, and V. Brandon, “Three-dimensional symmetry analysis of a direct-drive irradiation scheme for the laser megajoule facility,” Phys. Plasmas 21, 082710 (2014).10.1063/1.4893311
[16]	R. Ramis, B. Canaud, M. Temporal, W. J. Garbett, and F. Philippe, “Analysis of three-dimensional effects in laser driven thin-shell capsule implosions,” Matter Radiat. Extremes 4, 055402 (2019).10.1063/1.5095612
[17]	M. F. Modest, Radiative Heat Transfer, 3rd ed. (Academic Press; Elsevier, 2013), pp. 1–822.
[18]	G. Pomraning, The Equations of Radiation Hydrodynamics (Pergamon Press, Oxford, 1973), pp. 1–286.
[19]	H. A. Scott, J. A. Harte, M. E. Foord, and D. T. Woods, “Using tabulated NLTE data for hohlraum simulations,” Phys. Plasmas 29, 082703 (2022).10.1063/5.0102624
[20]	K. Eidmann, “Radiation transport and atomic physics modeling in high-energy-density laser-produced plasmas,” Laser Part. Beams 12, 223–244 (1994).10.1017/s0263034600007709
[21]	R. Ramis, R. Schmalz, and J. Meyer-ter-Vehn, “MULTI—A computer code for one-dimensional multigroup radiation hydrodynamics,” Comput. Phys. Commun. 49, 475–505 (1988).10.1016/0010-4655(88)90008-2
[22]	R. Ramis, J. Meyer-ter-Vehn, and J. Ramírez, “MULTI2D – a computer code for two-dimensional radiation hydrodynamics,” Comput. Phys. Commun. 180, 977–994 (2009).10.1016/j.cpc.2008.12.033
[23]	J. Meyer-ter-Vehn and R. Ramis, “On collisional free-free photon absorption in warm dense matter,” Phys. Plasmas 26, 113301 (2019).10.1063/1.5121218
[24]	E. Livne and A. Glasner, “A finite difference scheme for the heat conduction equation,” J. Comput. Phys. 58(1), 59–66 (1985).10.1016/0021-9991(85)90156-1
[25]	F. Wu, R. Ramis, and Z. Li, “A conservative MHD scheme on unstructured Lagrangian grids for Z-pinch hydrodynamic simulations,” J. Comput. Phys. 357, 206–229 (2018).10.1016/j.jcp.2017.12.014
[26]	Y. B. Zel’dovich and Y. P. Raizer, Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena (Academic Press, New York, 1967), pp. 1–488.
[27]	R. E. Marshak, “Effect of radiation on shock wave behavior,” Phys. Fluids 1, 24–29 (1958).10.1063/1.1724332
[28]	A. C. A Caruso and C. S. C Strangio, “The quality of the illumination for a spherical capsule enclosed in a radiating cavity,” Jpn. J. Appl. Phys. 30, 1095–1101 (1991).10.1143/jjap.30.1095
[29]	Y. Chen, Z. Li, X. Xie, C. Zheng, C. Zhai et al., “First experimental comparisons of laser-plasma interactions between spherical and cylindrical hohlraums at SGIII laser facility,” Matter Radiat. Extremes 2, 77–86 (2017).10.1016/j.mre.2017.01.001
[30]	W. A. Farmer, J. M. Koning, D. J. Strozzi, D. E. Hinkel, L. F. Berzak Hopkins et al., “Simulation of self-generated magnetic fields in an inertial fusion hohlraum environment,” Phys. Plasmas 24, 052703 (2017).10.1063/1.4983140
[31]	W. Y. Huo, Z. Li, Y.-H. Chen, X. Xie, G. Ren et al., “First octahedral spherical hohlraum energetics experiment at the SGIII laser facility,” Phys. Rev. Lett. 120, 165001 (2018).10.1103/physrevlett.120.165001
[32]	K. Lan, Y. Dong, J. Wu, Z. Li, Y. Chen et al., “First inertial confinement fusion implosion experiment in octahedral spherical hohlraum,” Phys. Rev. Lett. 127, 245001 (2021).10.1103/physrevlett.127.245001
[33]	Y.-H. Chen, Z. Li, H. Cao, K. Pan, S. Li et al., “Determination of laser entrance hole size for ignition-scale octahedral spherical hohlraums,” Matter Radiat. Extremes 7, 065901 (2022).10.1063/5.0102447
[34]	R. Sigel, G. D. Tsakiris, F. Lavarenne, J. Massen, R. Fedosejevs et al., “Experimental observation of laser-induced radiation heat waves,” Phys. Rev. Lett. 65, 587–590 (1990).10.1103/physrevlett.65.587