Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
Phys Chem Chem Phys. 2011 Nov 14;13(42):18954-61. doi: 10.1039/c1cp21277j. Epub 2011 Sep 7.
The guiding properties of individual rotational states of deuterated ammonia inside an electrostatic hexapole guide are presented. The guide is combined with resonance enhanced multiphoton ionization detection to assess the guiding probabilities and velocity distributions as a function of the rotational quantum numbers J and K. Due to the differences in the effective dipole moment these states are prepared at significantly different translational temperatures. A model is presented that describes the velocity-distribution for individual M-sublevels, and this model is also used to determine a rotational-state dependent translational temperature. Furthermore, the hexapole field has been replaced by a dipole field in order to obtain a band-pass velocity filter. However, the resulting change in the final velocity distribution is similar to that obtained from a hexapole guide but with increased backing pressure, leading to collisional acceleration of the slow molecules.
介绍了静电六极引导器中氘代氨的各个转动态的导向特性。该引导器与共振增强多光子电离检测相结合，以评估导向概率和速度分布作为转动量子数 J 和 K 的函数。由于有效偶极矩的差异，这些状态在明显不同的平移温度下被制备。提出了一个描述各个 M 亚能级速度分布的模型，该模型也用于确定与旋转状态相关的平移温度。此外，已经用偶极场代替了六极场，以获得带通速度滤波器。然而，最终速度分布的变化与从六极引导器获得的变化相似，但背压增加，导致慢分子的碰撞加速。
