高能离子在稠密等离子体中的传输和能量沉积

The energy deposition and propagation of fast ions in ultra-dense plasmas

用相对论福克-普朗克方程对高能离子在稠密氘氚等离子体中的碰撞动力学进行了研究,用球谐函数来展开方程的解:格林函数,然后简明地求出了不同能量质子和α粒子在等离子体中的停止时间、减速距离、纵向弥散距离和横向偏转距离.与以前研究离子在等离子体中运动的方法相比,没有假设高能离子在等离子体中损失能量远远小于入射离子能量,求解了纵向弥散距离;并且可以求解横向偏转距离.这些计算对实验上用高能离子加热冷的稠密等离子体,然后进行科学研究具有指导作用,并且可以用来研究快点火的可能性.

The collision dynamics of the fast ion population in ultra-dense DT plasmas are investigated and analyzed within the framework of the relativistic Fokker-Planck equation. The Green function expansing on the spherical harmonics is used to express the solution of the equation. With the Green function we can calculate the stopping time, the ion range, the straggling range, and the mean transverse dispersion of different kinds of ions in plasmas. Compared to the previous ways of studying the movement of ions in plasmas, we not only calculate the straggling range without the approximation that the energy loss of the ions is much smaller than the energy of the ions, but we also calculate the stopping time and the mean transverse dispersion. This calculation is important for the experimental study of high energy density plasmas and fast ignition of laser fusion.