Study of non-LTE photoionized plasma generated by laser-produced keV blackbody radiator

在天体物理学中，只要低温气体/等离子体沐浴在强辐射场中，就会遇到光电离等离子体。从CYGNUS X-3和VELA X-1等双星系统的吸积云中观测到了几keV光谱范围内的X射线线发射，其中来自致密物体（中子星、黑洞或白色矮星）的高强度X射线连续体照射冷的稀薄云。X射线连续诱导线发射准确地描述了吸积云，但这种光电离等离子体模型的实验验证是稀缺的。在这里，我们报告的光电离等离子体的产生在实验室条件下使用高功率激光。一个黑体辐射器在500 eV的温度下，对应于一个紧凑的对象，通过激光驱动的内爆。原子动力学计算意味着直接K壳层光电离的重要性，由传入的硬X射线。

Photoionized plasmas are encountered in astrophysics wherever low temperature gas/ plasma is bathed in a strong radiation field. X-ray line emissions in the several keV spectral range were observed from accreting clouds of binary systems, such as CYGNUS X-3 and VELA X-1, in which high-intensity x-ray continua from compact objects(neutron stars, black holes or white dwarfs) irradiate the cold and rarefied clouds. X-ray continuum-induced line emission accurately describes the accreting clouds, but experimental verification of this photoionized plasma model is scarce. Here we report the generation of photoionized plasmas in the laboratory under wellcharacterized conditions using a high-power laser. A blackbody radiator at a temperature of 500 eV, corresponding to a compact object, was created by means of a laser-driven implosion. Atomic kinetic calculations imply the importance of direct K-shell photoionization by incoming hard x-rays.