QuSeC-TAQS: Quantum Atomic Coherence-based Charged Particle Sensor

这个跨学科的项目将实施和测试一种新的方法来探测带电粒子束（例如电子束），使用基于原子光谱的量子传感方案与激光和微波。所提出的方法将通过非侵入性光学观测提供有关光束强度、位置、宽度、轮廓和方向的信息。这样，粒子束就可以不间断、不受干扰地连续监测。这种方法对核加速器中的高功率和高电流粒子束特别有用，因为在线探测器吸收的高功率使任何侵入性监测变得困难。提出的新量子传感器的基本思想是通过将“探测器”原子定位在带电粒子附近，通过它们的磁场或电场来检测带电粒子。由于这些场，这些原子的能级会发生变化，然后可以用激光或微波探针来测量。该项目将使用两种形式的铷原子作为探测介质：(1)室温下的热原子和(2)微开尔文温度下的超冷原子。研究生和本科生以及博士后研究员将接受原子物理、光学和量子科学技术以及粒子束物理方面的培训，为量子信息科学工作做好准备。该项目还将为公立和中学生开展量子科学的外展活动。这个跨学科项目是威廉玛丽学院的量子物理学家、托马斯杰斐逊国家加速器设施的核物理学家和MITRE公司的研究人员共同努力的结果。更广泛地说，带电粒子的探测在科学和工程的许多领域都有广泛的应用，从加速器和等离子体设施到国防和空间科学。具体来说，电子束产生的磁场将主要影响基态原子的自旋量子态，而电场将扰动原子的高激发态里德伯态。这些扰动可以通过激光场的光学性质（透射、偏振方向）的变化来检测，从而重建电子束的性质。该项目将包括三个主要任务。在第一个任务中，该团队将使用近室温的热铷原子来描绘电子束，以开发和优化实用的核物理束诊断设备。在第二项任务中，该团队将构建一个超冷原子装置，该装置将使用微波拉姆齐干涉和里德伯激发相结合来描绘电子束。这种无背景的方法有望具有高灵敏度，并具有检测单个电子轨迹的潜力。最后，在第三项任务中，该项目将研究使用非经典光学探针（如压缩光）来进一步提高超越量子标准极限的探测灵敏度。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This interdisciplinary project will implement and test a new approach for detecting charged particles beams (e.g., an electron beam) using quantum sensing schemes based on atomic spectroscopy with lasers and microwaves. The proposed method will provide information about the beam strength, position, width, profile, and direction via non-invasive optical observations. This way, a particle beam can be continuously monitored without interruptions or disturbances. This approach is particularly useful for high power and high current particle beams in nuclear accelerators, in which any invasive monitoring becomes difficult due to the high power absorbed by an in-line detector. The basic idea of the proposed new quantum sensor is to detect charged particles via their magnetic or electric field by positioning “detector” atoms in proximity of the charged particles. Such atoms will experience a shift in their energy levels due to these fields, which can then be measured using a laser or microwave probe. The project will use rubidium atoms in two forms as the detection medium: (1) thermal atoms at room temperature and (2) ultracold atoms at micro-Kelvin temperatures. Graduate and undergraduate students, as well as a postdoctoral researcher, will be trained in atomic physics, optics, and quantum science techniques, as well as particle beam physics, in preparation for the quantum information science workforce. The project will also conduct outreach activities in quantum science for the public and secondary school students. This interdisciplinary project is a collaborative effort between quantum physicists at the College of William & Mary, nuclear physicists at the Thomas Jefferson National Accelerator Facility, and researchers at MITRE Corporation. More broadly, the detection of charged particles has broad applications across many areas of science and engineering, from accelerator and plasma facilities to defense and space science.More specifically, the electron-beam generated magnetic field will primarily affect the spin quantum state of ground state atoms, while the electric field will perturb the highly excited Rydberg state of atoms. These perturbations can be detected via changes in the optical properties (transmission, polarization direction) of a laser field to reconstruct the properties of the electron beam. The project will consist of three main tasks. In the first task, this team will employ near-room temperature thermal rubidium atoms to profile an electron beam to develop and optimize a practical beam diagnostic device for nuclear physics. In a second task, this team will construct an ultracold atom apparatus that will profile an electron beam using microwave Ramsey interference in combination with Rydberg excitation. This background-free approach is expected to have high sensitivity and has the potential for detecting single electron tracks. Finally, in a third task, the project will investigate the use of non-classical optical probes (such as squeezed light) to further improve the detection sensitivity beyond the quantum standard limit.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.