Precision measurements of cold atom - hot gas collisions.

激光冷却和俘获原子使基础科学和应用技术发生了革命性的变化。事实上，冷原子现在是制造最精确时钟的基本构件，它们可以用来制造人类已知的最灵敏的重力计和加速计。这些技术革命性地改变了计时、通信、遥测和惯性制导技术，极大地影响了社会。这种技术影响的一个普遍例子是全球定位系统，它依赖于基于卫星的原子钟的同步。这项研究计划计划的目标是使用冷的、被捕获的原子来测量真空环境中被捕获的原子与热的背景气体之间的碰撞。这些测量将使我们能够区分弹性、非弹性和反应性碰撞过程，从而能够研究粒子之间的远程相互作用。这项工作的一个好处是，它提供了根据陷阱损失测量来定义高真空和超高真空范围的压力标准的机会。一个被困在浅势中的冷原子是探测真空中其他粒子的近乎理想的候选者。当粒子穿过被捕获原子的碰撞截面时，一些动量被传递给静止的原子。碰撞是通过从陷阱中失去原始的“传感器”原子来检测的。这些测量不受传感器退化或校准漂移的影响，因为碰撞是由粒子的不变物理属性控制的。拟议的研究计划将扩展我与柯克·麦迪逊(UBC)的合作，实现高精度的碰撞测量，并产生一种新的压力测量技术。预计将产生重大影响的是创建第一个特高压范围内压力的主要标准。该研发计划可以扩展到生产一种基于冷原子的压力装置，能够取代现有的基于电离的真空计量，据估计，北美的真空计量市场每年价值1.7亿美元。因此，拟议的研究计划将是一种有效的知识动员形式，为加拿大带来商业上有用的创新和经济效益。

Laser cooled and trapped atoms have revolutionized basic science and applied technologies. Indeed, cold atoms are now the fundamental building block for the most precise clock that can be made, and they can be used to create the most sensitive gravitometer and accelerometer known to man. These technologies have dramatically impacted society by revolutionizing time-keeping, communication, telemetry, and inertial guidance technologies. A ubiquitous example of the impact of this technology is the Global Positioning System which relies on the synchronization of satellite-based atomic clocks. This research program proposal, has the goal of using cold, trapped atoms for measuring collisions between the trapped atoms and hot, background gases in the vacuum environment. These measurements will allow us to distinguish between elastic, inelastic, and reactive collision processes, enabling the study of the long range interactions between particles. One benefit of this work is that it affords the opportunity to define a pressure standard for the high-vacuum and ultra-high vacuum ranges based on trap loss measurements. A cold atom, trapped in a shallow potential, is a near ideal candidate to detect other particles in a vacuum. When a particle passes through the collision cross-section of the trapped atom, some momentum is transferred to the stationary atom. The collision is detected via the loss of the original “sensor” atom from the trap. These measurements are not subject to sensor degradation or calibration drift since the collisions are governed by the immutable physical properties of the particles. The proposed research program will extend my collaborative work with Kirk Madison (UBC) and lead to the realization of high precision collision measurements and produce a new pressure measurement technology. A significant impact is expected to be the creation of the first primary standard for pressure in the UHV range. The research and development program can be extended to produce a cold atom-based pressure device capable of superseding the existing, ionization-based vacuum metrology, a market estimated at $170 million per year in North America. Therefore, the proposed research program will be an effective form of knowledge mobilization resulting in commercially useful innovation and economic benefit for Canada.