Electron Beam Characterization via Quantum Coherent Optical Magnetometry

TL;DR

This paper introduces a quantum optics-based, non-invasive method to determine the position, size, and current of electron beams by measuring magnetic field-induced polarization rotation in rubidium vapor, applicable across various energies.

Contribution

The paper presents a novel quantum coherent optical magnetometry technique for electron beam characterization, insensitive to electron kinetic energy, enabling non-invasive measurements.

Findings

Effective detection of electron beam position and current.

Method works for electron energies between 10 to 20 keV.

Insensitive to electron kinetic energy variations.

Abstract

We present a quantum optics-based detection method for determining the position and current of an electron beam. As electrons pass through a dilute vapor of rubidium atoms, their magnetic field perturb the atomic spin's quantum state and causes polarization rotation of a laser resonant with an optical transition of the atoms. By measuring the polarization rotation angle across the laser beam, we recreate a 2D projection of the magnetic field and use it to determine the e-beam position, size and total current. We tested this method for an e-beam with currents ranging from 30 to 110 {\mu}A. Our approach is insensitive to electron kinetic energy, and we confirmed that experimentally between 10 to 20 keV. This technique offers a unique platform for non-invasive characterization of charged particle beams used in accelerators for particle and nuclear physics research.