Code O-SUKI: Simulation of direct-drive fuel target implosion in heavy ion inertial fusion

Abstract

The Code O-SUKI is an integrated 2-dimensional (2D) simulation program system for a fuel implosion, ignition and burning of a direct-drive nuclear-fusion pellet in heavy ion beam (HIB) inertial confinement fusion (HIF). The Code O-SUKI consists of the four programs of the HIB illumination and energy deposition program of OK3 (Comput. Phys. Commun. 181, 1332 (2010)), a Lagrangian fluid implosion program, a data conversion program, and an Euler fluid implosion, ignition and burning program. The OK3 computes the multi-HIBs irradiation onto a spherical fuel target. One HIB is divided into many beamlets in OK3. Each heavy ion beamlet deposits its energy along the trajectory in a deposition layer depending on the particle energy. The OK3 also has a function of a wobbling motion of the HIB axis oscillation, and the HIBs energy deposition spatial detail profile is obtained inside the energy absorber of the fuel target. The spherical target implosion 2D behavior is computed by the 2D Lagrangian fluid code coupled with OK3, until just before the void closure time of the fuel implosion. After that, all the data by the Lagrangian implosion code are converted to them for the Eulerian code. The fusion Deuterium (D)–Tritium (T) fuel and the inward moving heavy tamping material are imploded and deformed seriously at the stagnation phase. The Euler fluid code is appropriate to simulate the fusion fuel compression, ignition and burning. The Code O-SUKI 2D simulation system provides a capability to compute and to study the HIF target implosion dynamics. Program summaryProgram Title: O-SUKIProgram Files doi:http://dx.doi.org/10.17632/h8n474wvf5.1Licensing provisions: CC BY NC 3.0Programming language: C++Nature of problem: The nuclear fusion energy would provide one of energy resources for our human society. In this paper we focus on heavy ion beam (HIB) inertial confinement fusion (HIF). A spherical deuterium (D)–tritium (T) fuel pellet, whose radius may be about several mm, is irradiated by HIBs to be compressed to about a thousand times of the solid density. The DT fuel temperature reaches ∼5–10 KeV to be ignited to release the DT fusion energy. The typical HIBs total input energy is several MJ, and the HIBs pulse length is about a few tens of ns. The DT fuel compression uniformity is essentially important to release the sufficient fusion energy output. The DT fuel pellet implosion non-uniformity should be kept less than a few %. The O-SUKI code system provides an integrated tool to simulate the HIF DT fuel pellet implosion, ignition and burning. The HIBs energy deposition detail profile is computed by the OK3 code (Comput. Phys. Commun. 181, 1332 (2010)) in an energy absorber outer layer, which covers the DT fuel spherical shell. The DT fuel is compressed to the high density, and so the DT fuel spatial deformation may be serious at the DT fuel stagnation. Therefore, the O-SUKI system employs a Lagrangian fluid code first to simulate the DT fuel implosion phase until just before the stagnation. Then all the simulation data from the Lagrangian code are converted to them for the Euler fluid code, in which the DT fuel ignition and burning are simulated.Solution method: In the two fluids codes (Lagrangian and Euler fluid codes) in the O-SUKI system the three-temperature fluid model (J. Appl. Phys. 60, 898 (1986)) is employed to simulate the pellet dynamics in HIF. The HIBs energy deposition detail profile is computed by the OK3 code (Comput. Phys. Commun. 181, 1332 (2010)).