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arXiv 2310.04583physics.atom-ph
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残余气体碰撞驱动的被困粒子演化

Trapped particle evolution driven by residual gas collisions

Avinash Deshmukh, Riley A. Stewart, Pinrui Shen, James L. Booth, Kirk W. Madison

备注：
14 pages, 6 figures
发表信息：
Phys. Rev. A Vol. 109, Iss. 3 March 2024
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AI总结：

提出一种基于碰撞诱导能量转移概率分布函数的模型，精确描述残余气体碰撞下被困粒子系综的演化，并通过实验验证，碰撞率提取精度提升五倍。

摘要：

我们提出了一个全面的数学模型和实验测量，用于描述由室温背景蒸气碰撞驱动的被困粒子系综的演化。该模型适用于任意陷阱几何形状、约束势、初始被困分布及其他实验细节；它仅依赖于碰撞诱导能量转移到被困系综的概率分布函数$P_t(E)$。我们描述了如何利用量子散射计算找到$P_t(E)$，以及如何通过量子衍射普适性对其进行近似。然后，我们将模型与暴露于室温Ar背景气体的$^{87}$Rb系综能量演化的实验测量进行比较，通过单参数拟合总碰撞率$Γ$。我们提取的碰撞率为$Γ= 0.646(1)\ \ ext{s}^{-1}$。这与常用方法零陷阱深度外推得到的$0.664(4)\ \ ext{s}^{-1}$值进行比较，显示出$2.8\%$的修正，这是我们的模型充分考虑系综损失和加热的结果。最后，我们报告了从实验数据中提取碰撞率的精度提高了五倍。

英文摘要：

We present a comprehensive mathematical model and experimental measurements for the evolution of a trapped particle ensemble driven by collisions with a room-temperature background vapor. The model accommodates any trap geometry, confining potential, initial trapped distribution, and other experimental details; it only depends on the the probability distribution function $P_t(E)$ for the collision-induced energy transfer to the trapped ensemble. We describe how to find $P_t(E)$ using quantum scattering calculations and how it can be approximated using quantum diffractive universality. We then compare our model to experimental measurements of a $^{87}$Rb ensemble energy evolution exposed to a room temperature background gas of Ar by means of a single parameter fit for the total collision rate $Γ$. We extracted a collision rate of $Γ= 0.646(1)\ \text{s}^{-1}$. This is compared to a value of $0.664(4)\ \text{s}^{-1}$ found by the commonly used method of zero-trap depth extrapolation, a $2.8\%$ correction that is a result of our model fully taking ensemble loss and heating into account. Finally, we report a five-fold increase in the precision of our collision rate extraction from the experimental data.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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