软X射线激光探针诊断高Z材料等离子体

Diagnosis of high-Z plasma with soft X-ray laser probe

激光辐照靶产生的等离子体电子密度的诊断对于惯性约束聚变、高能量密度物理等相关领域的研究具有重要意义,特别是高Z材料等离子体临界面附近的电子密度分布信息的测量.利用软X射线激光作为探针是诊断等离子体电子密度分布的一种重要方法,但在诊断激光辐照高Z材料产生的等离子体研究中,遇到了高Z材料等离子体自发辐射过大的问题,难以开展.为此,针对软X射线激光的特点,发展了多种具体的实验技术.通过综合利用这些技术,大大的抑制了待测等离子体自发辐射对信号的影响,使得软X射线激光探针诊断高Z材料等离子体成为可能.作为典型例子,实验诊断了激光辐照金平面靶的等离子体,获得了清晰的实验图像,表明相关的技术是有效和可行的.

It is important to diagnose electron density of a plasma irradiated by lasers for inertial confinement fusion, in high energy density physics and related fields, especially for measuring high-Z plasma near the interface. Use of soft X-ray laser as a probe is an important method in diagnosis of plasma electron density distribution. However, it is difficult to carry out the research in high-Z laser plasma, because of the problem of excessive plasma spontaneous radiation. In view of the characteristics of soft X-ray laser, several specific experimental techniques have been developed. By using these techniques, which can greatly suppress effects of spontaneous radiation, diagnosis of high-Z plasma with soft X-ray laser probe method becomes possible. As a typical example, an experiment of diagnosing gold plasma is performed and clear images are obtained, indicating that the techniques are effective and feasible.