Non-intrusive measurement of magnetic field strengths in a low-pressure argon plasma using quantum beat spectroscopy

Journal Article · 27 February 2025 · Plasma Sources Science and Technology

DOI: https://doi.org/10.1088/1361-6595/adb784 · OSTI ID:2525961

Gilbert, Tyler J. ; Steinberger, Thomas E. ; Scime, Earl E.

Abstract Accurate measurement of magnetic field strengths is critical in many plasma environments, ranging from astrophysical systems to fusion energy research. In this work, a non-perturbative laser-based optical diagnostic known as quantum beat spectroscopy is demonstrated to be good alternative for measuring the magnetic field strength in low-pressure laboratory plasmas. The technique is investigated using both ns and fs pulsed lasers in an argon plasma. Preliminary results for a helium plasma are also given. Zeeman-split J  = 1 electron states with transitions from metastable states were identified and tested for neutral argon ${(}^2{\text{P}}_{1/2}^{\text{o}})4p$ ${}^2\left[1/2\right]$ and neutral helium $1s3p$ ${}^1{P}_1^{\text{o}}$ . Magnetic fields are measured with sub-Gauss precision at near single laser pulse acquisition rates.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0020294
• OSTI ID: 2525961
• Journal Information: Plasma Sources Science and Technology, Journal Name: Plasma Sources Science and Technology Journal Issue: 2 Vol. 34; ISSN 0963-0252
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United Kingdom
• Language: English