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

College Of William And Mary, Williamsburg VA

Investigators

Abstract

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.