氩团簇高信噪比13—23nm软x射线辐射谱实验观察

用150fs的掺钛蓝宝石激光系统, 在功率密度约为5×10¹⁵ W/cm²时 激励氩(Ar)团簇，利用具有空间分辨能力的平场光栅谱仪观察到13—23nm波段Ar的软x射线谱，并观察到Ar的11阶离子谱线.在较宽的激光脉宽和较低的激光功率密度情况下，通过激励Ar团簇，获得 了Ar的高阶电离度的实验结果，且谱线的信噪比明显好于光场感应电离的情况，说明团簇的 形成大幅度地提高了激光能量的吸收效率.关键词：Ar团簇超短强激光软x射线辐射

Soft-x-ray emission from Ar clusters irradiated by 150fs laser pulses

Soft x-ray emission from Ar clusters irradiated by intense 150 fs laser pulses a t an intensity of～5×10¹⁵ W/cm² has been measured with a flat field spe ctrometer. Strong transitions from ArⅧ charge states have been observed, some s pectral lines belong to ArⅫ and ArⅩⅢ. Compared with optical field ionization, the interaction of intense laser pulse with clusters enhances drastically the a bsorption of laser energy and higher charge states are obtained as well. The sig nificant change in the spectrum is attributed to the collisinal heating of small -sized Ar clusters formed at on enough baking pressure of gas.