乙醚团簇在纳秒激光场中的多价电离及其电子能量分布的研究

用5ns，1064nm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10¹¹ W/cm²量级光强下，观察到价电子完全剥离的O⁶⁺，C⁴⁺，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4.0×10¹¹ W/cm²，溢出电子的平均能量为56eV，最大能量为102eV.实验结果支持了高价离子产生的“多 关键词： 高价离子 电子能量 纳秒激光 乙醚团簇

Multiple ionization of diethyl ether cluster by nanosecond laser: generation of multiply charged ions and the electron energy distribution

The interaction of diethyl ether clusters and laser was studied at laser intensity of 10¹¹ W/cm² using 5 ns, 1064 nm laser pulses. Multiply charged ions O⁶⁺ and C⁴⁺ were observed and the ratio of O⁶⁺/C⁴⁺ 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 4.0×10¹¹ W/cm², the mean electron energy of 56eV and the maximum electron energy of 102eV 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”.