中文摘要：

用5 ns,1064 nm的脉冲Nd：YAG激光,研究了乙醚团簇与纳秒激光的相互作用.在10^11W/cm^2量级光强下,观察到价电子完全剥离的O^6＋,C^4＋,且这些高价离子的强度比值基本不随激光能量而变化.用阻滞电压方法测量了电离过程中溢出电子能量分布,在最大激光能量4.0×10^11W/cm^2,溢出电子的平均能量为56 eV,最大能量为102 eV.实验结果支持了高价离子产生的“多光子电离引发-逆韧致吸收加热-电子碰撞电离”三步模型,表明电子碰撞电离是高价离子形成的主要途径.另外,计算结果表明,团簇中电子-离子的库仑屏蔽可以有效降低高价离子的电离势,促进高价离子的产生.

英文摘要：

The interaction of diethyl ether clusters and laser was studied at laser intensity of 10^11 W/cm^2 using 5 ns, 1064 nm laser pulses. Multiply charged ions O^6＋ and C^4＋ were observed and the ratio of O^6＋/C^4＋ nearly kept constant in the range of laser intensity studied. The energy distribution of electrons ejected was measured via retarding potential method. At the laser intensity of 4.0 × 10^11 W/cm^2 , the mean electron energy of 56 eV and the maximum electron energy of 102 eV were observed. It indicates that the multiply charged ions are mainly produced from energetic electron impact ionization. In addition, our calculated results show that the screening effect inside cluster can significantly decrease the ionization potentials of multiply charged ions, thus facilitating the ionization especially at low laser intensity. The above results further support our three stage model of ＂multiphoton ionization ignition-inverse bremsstrahlung heating-electron impact ionization＂.