【摘要】 利用脉宽为25ns的脉冲Nd:YAG1064nm激光,在1010～1011W·cm-2强度下,用飞行时间质谱对乙腈分子束激光电离过程进行了研究,发现了高价态的原子离子Nq+(q=1～5)和Cq+(q=1～4).类氦离子N5+、C4+的最可几平动能分别高达566eV和427eV.激光延时以及不同束源压力的实验结果表明,这些高价离子可能来源于乙腈团簇的库仑爆炸过程.提出一个多光子电离引发,逆韧致吸收加热-电子碰撞电离模型来解释高价离子的产生.更多还原

【Abstract】 The photoionization of acetonitrile seeded in helium is studied by time-of-flight mass spectrometry using a 25 ns, 1064 nm Nd:YAG laser with intensity near 1011 W·cm-2. Multiply charged ions of Nq+(q=1～5)和Cq+(q=1～4) with hundreds of eV have been observed under laser beam irradiation with the densest portion of the pulsed molecular beam. An electron re-scattering and re-colliding ionization model is proposed to explain the generation of those multiply charged clusters under such low laser intensity.更多还原