【摘要】 用 1 50fs的掺钛蓝宝石激光系统 ,在功率密度约为 5× 1 0 1 5W 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 1 3— 2 3nm波段Ar的软x射线谱 ,并观察到Ar的 1 1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更多还原

【Abstract】 Soft x-ray emission from Ar clusters irradiated by intense 150 fs laser pulses at an intensity of～5×10 15 W/cm 2 has been measured with a flat field sp ectrometer. Strong transitions from ArⅧ charge states have been observed, som e spectral lines belong to ArⅫ and ArⅩⅢ. Compared with optical fie ld ioniz ation, the interaction of intense laser pulse with clusters enhances drastically the absorption of laser energy and higher charge states are obtained as well. T he significant change in the spectrum is attributed to the collisinal heating of small-sized Ar clusters formed at on enough baking pressure of gas.更多还原