Nag Pamir, Nandi Dhananjay
Indian Institute of Science Education and Research, Kolkata, Mohanpur, Nadia 741246, India.
Phys Chem Chem Phys. 2015 Mar 21;17(11):7130-7. doi: 10.1039/c4cp05678g.
Complete dissociation dynamics in electron attachment to carbon monoxide (CO) have been studied using the newly developed velocity slice imaging (VSI) technique. Both kinetic energy and angular distributions of O(-) ions formed by dissociative electron attachment (DEA) to CO molecules have been measured for 9, 9.5, 10, 10.5, 11, and 11.5 eV incident electron energies around the resonance. Detailed observations conclusively show that two separate DEA reactions lead to the formation of O(-) ions in the ground (2)P state along with the neutral C atoms in the ground (3)P state and the first excited (1)D state, respectively. Within the axial recoil approximation and involving four partial waves, our angular distribution results clearly indicate that the two reactions leading to O(-) formation proceed through the specific resonant state(s). For the first process, more than one intermediate state is involved. On the other hand, for the second process, only one state is involved. The observed forward-backward asymmetry is explained in terms of the interference between the different partial waves that are involved in the processes.
利用新开发的速度切片成像（VSI）技术研究了电子附着于一氧化碳（CO）时的完全解离动力学。对于共振附近9、9.5、10、10.5、11和11.5 eV的入射电子能量，测量了通过解离电子附着（DEA）到CO分子形成的O(-)离子的动能和角分布。详细观察结果确凿地表明，两个独立的DEA反应分别导致基态（2）P态的O(-)离子与基态（3）P态和第一激发态（1）D态的中性C原子的形成。在轴向反冲近似范围内并涉及四个分波，我们的角分布结果清楚地表明，导致O(-)形成的两个反应通过特定的共振态进行。对于第一个过程，涉及多个中间态。另一方面，对于第二个过程，只涉及一个态。观察到的前后不对称性是根据过程中涉及的不同分波之间的干涉来解释的。
