JILA, National Institute of Standards and Technology and the University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
Phys Chem Chem Phys. 2011 Nov 14;13(42):19059-66. doi: 10.1039/c1cp21203f. Epub 2011 Sep 1.
Cold molecules promise to reveal a rich set of novel collision dynamics in the low-energy regime. By combining for the first time the techniques of Stark deceleration, magnetic trapping, and cryogenic buffer gas cooling, we present the first experimental observation of cold collisions between two different species of state-selected neutral polar molecules. This has enabled an absolute measurement of the total trap loss cross sections between OH and ND(3) at a mean collision energy of 3.6 cm(-1) (5 K). Due to the dipolar interaction, the total cross section increases upon application of an external polarizing electric field. Cross sections computed from ab initio potential energy surfaces are in agreement with the measured value at zero external electric field. The theory presented here represents the first such analysis of collisions between a (2)Π radical and a closed-shell polyatomic molecule.
冷分子有望揭示低能区丰富的新型碰撞动力学。通过首次结合斯塔克减速、磁阱和低温缓冲气体冷却技术，我们首次实验观察到两种不同态选择中性极性分子之间的冷碰撞。这使得能够在平均碰撞能量为 3.6 cm(-1)（5 K）的情况下对 OH 和 ND(3)之间的总陷阱损耗截面进行绝对测量。由于偶极相互作用，在外加极化电场的作用下，总截面会增加。从头算势能面计算的截面与零外电场下的测量值一致。这里提出的理论代表了对（2）Π 自由基与封闭壳多原子分子之间碰撞的首次此类分析。
