Experimental search for scattering resonances in near cold molecular collisions
Experimental search for scattering resonances in near cold molecular collisions
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近冷分子碰撞中散射共振的实验研究
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Costes
中科院分区：
文献类型：
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作者：
C. Naulin;M. Costes
我们回顾了在相当于几个开尔文温度的能域内发生的分子碰撞中的散射共振的实验结果。我们讨论了观察形状(或轨道)和费什巴赫共振所需的条件，在所有情况下，关键因素都是这个过程中涉及的分波的数量。这意味着使用匹配和低速、高速度分辨率和低波束交叉角的超音速波束。这是弹性、非弹性和反应性碰撞的例子，在这些碰撞中，使用了不同的策略，因此使用了实验安排。我们回顾了自20世纪70年代以来首次在弹性碰撞中观察到的共振现象，以及最近在非弹性碰撞和反应性碰撞中的结果。最显著的结果是O_2+准H_2非弹性碰撞，它的转动激发是通过纯量子过程发生的，在积分截面上产生了一个很好分辨的结构，被指定为确定的、分离良好的分波。
We review the experimental findings on scattering resonances in molecular collisions occurring in the energy domain equivalent to temperatures of a few Kelvin. We discuss the conditions required to observe shape (or orbiting) and Feshbach resonances, the crucial factor being in all cases the number of partial waves involved in the process. This implies operating with supersonic beams with matched and low velocities, high velocity resolution and low beam-intersection angle. This is exemplified for elastic, inelastic and reactive collisions, where different strategies, thence experimental arrangements, are used. We review the first observation of resonances in elastic collisions from the 1970s and the recent results in inelastic and reactive collisions. The most striking result is obtained for O2 + para-H2 inelastic collisions for which rotational excitation occurs through a pure quantum process, yielding a well-resolved structure in the integral cross section assigned to definite well-separated partial waves.