Wang Yanmei, Zhang Song, Wei Zhengrong, Zhang Bing
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.
J Phys Chem A. 2008 May 1;112(17):3846-51. doi: 10.1021/jp711032z. Epub 2008 Mar 26.
The dissociative ionization and the Coulomb explosion of CH3I irradiated by a 35 fs 800 nm laser with a laser intensity of 4 x 10(13) to 6 x 10(14) W/cm2 was studied. In a relatively weak laser field (about 10(13) W/cm2), the dissociative ionization of CH3I took place. The speed distributions of the CH3+ and I+ fragments were measured and fitted using multiple Gaussian functions. Different product channels were found for CH3+ and I+, respectively. In a strong laser field (about 10(14) W/cm2), the multiply ionized fragment ions of Iq+ (q </= 3), which experienced a Coulomb explosion, were observed. The angular and speed distributions of the I+, I2+, and I3+ fragments were obtained. All of these fragment angular distributions are anisotropic and peaked along the laser polarization direction. The Iq+ ion angular distributions all were of similar widths, which would imply that the geometric alignment dominated the process, as opposed to a dynamic alignment mechanism.
研究了用脉宽为35飞秒、波长为800纳米、激光强度为4×10¹³至6×10¹⁴瓦/平方厘米的激光辐照CH₃I时的离解电离和库仑爆炸。在相对较弱的激光场（约10¹³瓦/平方厘米）中，CH₃I发生了离解电离。测量了CH₃⁺和I⁺碎片的速度分布，并使用多个高斯函数进行拟合。分别为CH₃⁺和I⁺发现了不同的产物通道。在强激光场（约10¹⁴瓦/平方厘米）中，观察到经历库仑爆炸的Iq⁺（q≤3）的多电离碎片离子。获得了I⁺、I₂⁺和I₃⁺碎片的角度和速度分布。所有这些碎片角度分布都是各向异性的，并且沿激光偏振方向达到峰值。Iq⁺离子角度分布都具有相似的宽度，这意味着几何排列主导了该过程，而不是动态排列机制。
