论文标题
低密度状态下分子的缓冲气热冷却：模拟与实验之间的比较
Buffer-gas cooling of molecules in the low-density regime: Comparison between simulation and experiment
论文作者
论文摘要
在过去的几十年中，低温缓冲气体细胞一直是分子冷却的主力。直接的同情冷却原理使它们适用于各种不同的物种。尽管取得了成功，但对缓冲气体电池的详细模拟很少见，并且从未与低至中间缓冲气体密度的实验数据进行比较。在这里，我们提出了一种基于轨迹分析的数值方法，由于与均匀的缓冲液气体发生碰撞，分子在细胞中随机行走。该方法可以重现从缓冲液池中出现的分子的实验通量和速度分布，以使缓冲气体密度不同。这包括从细胞中的分子输出的强大减少，以增加缓冲气体密度和所谓的增强效果，当分子在离开细胞后通过缓冲液原子加速时。这些模拟提供了各种见解，可以大大改善缓冲气体的设计。
Cryogenic buffer gas cells have been a workhorse for the cooling of molecules in the last decades. The straightforward sympathetic cooling principle makes them applicable to a huge variety of different species. Notwithstanding this success, detailed simulations of buffer gas cells are rare, and have never been compared to experimental data in the regime of low to intermediate buffer gas densities. Here, we present a numerical approach based on a trajectory analysis, with molecules performing a random walk in the cell due to collisions with a homogeneous buffer gas. This method can reproduce experimental flux and velocity distributions of molecules emerging from the buffer gas cell for varying buffer gas densities. This includes the strong decrease in molecule output from the cell for increasing buffer gas density and the so-called boosting effect, when molecules are accelerated by buffer-gas atoms after leaving the cell. The simulations provide various insights which could substantially improve buffer-gas cell design.
