Laser-induced-fluorescence imaging of a spin-polarized ultracold neutral plasma in a magnetic field

Journal Article · 18 January 2022 · Physical Review A

DOI: https://doi.org/10.1103/physreva.105.013108 · OSTI ID:1982744

Gorman, G. M.  ^[1]; Warrens, M. K.  ^[1]; Bradshaw, S. J. ^[1]; Killian, T. C.  ^[1]

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1. Rice Univ., Houston, TX (United States)

In this work, we report Doppler-sensitive laser-induced-fluorescence (LIF) imaging of an ultracold neutral plasma in a magnetic field. Local values of ion density, hydrodynamic fluid velocity, temperature, and spin polarization are obtained using a fluorescence model based on velocity-resolved rate equations (REs) including the transfer of ions between states due to laser coupling and spontaneous emission. The RE approach captures optical pumping of ions into states that are not driven by the LIF excitation laser, and this is validated with experimental data. Combined molecular-dynamics and quantum-trajectories simulations verify that velocity-changing collisions have a negligible impact on the state population evolution for typical experimental conditions. Relative intensities of Zeeman components of the LIF spectra provide clear evidence that the ions are electron-spin-polarized when created by photoionization of magnetically trapped ⁸⁸Sr atoms. This probe opens many possibilities for studying thermal transport and the equilibration of neutral plasmas in overlapping regimes of strong coupling and magnetization.

• Research Organization: US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Fusion Energy Sciences (FES)
• Sponsoring Organization: National Science Foundation (NSF); US Air Force Office of Scientific Research (AFOSR); USDOE
• OSTI ID: 1982744
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 1 Vol. 105; ISSN 2469-9926
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English