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Multi-dimensional transport-hydrodynamic analysis of the roles of fusion-produced particles in inertial fusion plasmas

惯性聚变等离子体中聚变产生的粒子作用的多维输运流体动力学分析

基本信息

批准号：
12680492
负责人：
NAKAO Yasuyuki
金额：
$ 1.22万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

The purpose of the present study is to investigate the role of fusion-produced particles in ICF plasma, on the basis of multi-dimensional transport-hydrodynamic calculations. First, we developed two-dimensional transport and diffusion codes for alpha-particles, and verified usefulness of these codes in analyzing the effects of alpha-particle heating.The developed diffusion code was coupled with a radiation-hydrodynamic code to investigate how and to what extent the hydrodynamic instability in the stagnation phase affects the ignition and burn property of compressed fuel spheres. As an initial condition, we assumed a fuel sphere at the stagnation phase and applied a sinusoidal single mode perturbation to the density, temperature and fluid velocity profiles in the boundary region between the hot spark and main fuel. It was confirmed that once a certain amount of fusion reactions occur in the spark region, the initial perturbations are drastically smoothed by the alpha-particle heating. It was also found that the amplitudes of the initial perturbations should be less than 5% of the hot spot radius in order to achieve a sufficient fuel gain (>1000).In the latter half of the study, our attention was directed to the code plasma heating and ignition process in the fast ignition scheme. To this end, we developed a kinetic transport code for relativistic electrons. In addition to binary collisions at short range, we considered long-range collisions between screened particles. Given the source distribution of beam electrons entering the core region, the code is capable of calculating the time-and space-dependent plasma heating rate.This code was coupled with a radiation-hydrodynamic one to analyze the core-plasma heating experiment carried out at Osaka Univ. The simulation explained the observed neutron production. Then, we examined the ignition and burn properties of compressed fuels of various sizes, and finally evaluated the gain curves.

本研究的目的是研究聚变产生的粒子在ICF等离子体中的作用，在多维输运流体动力学计算的基础上。首先，我们开发了二维α粒子输运和扩散程序，验证了这些程序在分析α粒子加热效应方面的有效性，并将所开发的扩散程序与辐射流体动力学程序耦合，研究了停滞阶段的流体动力学不稳定性如何以及在多大程度上影响压缩燃料球的点火和燃烧特性。作为初始条件，我们假设在停滞阶段的燃料球，并施加一个正弦单模扰动的密度，温度和流体速度分布在热火花和主燃料之间的边界区域。据证实，一旦一定量的聚变反应发生在火花区，初始扰动急剧平滑的α粒子加热。为了获得足够的燃料增益（>1000），初始扰动的幅值应小于热点半径的5%。在后半部分的研究中，我们的注意力集中在快速点火方案中的等离子体加热和点火过程的代码。为此，我们开发了相对论电子的动力学输运代码。除了在短距离的二元碰撞，我们认为屏蔽粒子之间的远程碰撞。在给定进入堆芯区的束流电子源分布的情况下，该程序能够计算等离子体加热率随时间和空间的变化，并与辐射流体动力学程序耦合，对大坂大学进行的堆芯等离子体加热实验进行了模拟，解释了中子产生的原因。然后，我们研究了不同尺寸的压缩燃料的点火和燃烧特性，最后评估了增益曲线。