Ultracold neutral plasma expansion in a strong uniform magnetic field.
| Autor: | Sprenkle RT; Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA., Bergeson SD; Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA., Silvestri LG; Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, Michigan 48824, USA., Murillo MS; Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, Michigan 48824, USA. |
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| Jazyk: | angličtina |
| Zdroj: | Physical review. E [Phys Rev E] 2022 Apr; Vol. 105 (4-2), pp. 045201. |
| DOI: | 10.1103/PhysRevE.105.045201 |
| Abstrakt: | In strongly magnetized neutral plasmas, electron motion is reduced perpendicular to the magnetic field direction. This changes dynamical plasma properties such as temperature equilibration, spatial density evolution, electron pressure, and thermal and electrical conductivity. In this paper we report measurements of free plasma expansion in the presence of a strong magnetic field. We image laser-induced fluorescence from an ultracold neutral Ca^{+} plasma to map the plasma size as a function of time for a range of magnetic field strengths. The asymptotic expansion velocity perpendicular to the magnetic field direction falls rapidly with increasing magnetic field strength. We observe that the initially Gaussian spatial distribution remains Gaussian throughout the expansion in both the parallel and perpendicular directions. We compare these observations with a diffusion model and with a self-similar expansion model and show that neither of these models reproduces the observed behavior over the entire range of magnetic fields used in this study. Modeling the expansion of a magnetized ultracold plasma poses a nontrivial theoretical challenge. |
| Databáze: | MEDLINE |
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