The ponderomotive force has previously been identified as a possible driver of observed density modifications close to radio frequency actuators during operation. This nonlinear force redistributes density in regions of gradients in the magnitude of an oscillating electric field and describes the influence of the fast time scale RF wave dynamics on slow time scale plasma transport. Depletion of the saturation current (a proxy for the density) measured at the Large Plasma Device (LAPD) was 30–35% during ion cyclotron range of frequencies operation. A coupled 1D plasma transport and cold plasma frequency domain wave solver was developed to self-consistently describe ponderomotive effects and was used to compare with results obtained from the LAPD experiment. The scaled current density driver for the wave model yielded an RF B field in close agreement with two components of the experimental data. However, the 1D parallel model did not accurately reproduce the amplitude or spatial distribution observed in experimental measurements of By. Within the limitations of the 1D model, initial simulation results showed that the ponderomotive force depleted up to 8% for high power (1 MW) and around 1% for the experimental power of 120 kW. This could suggest that the ponderomotive force is not the main driver of density modification for the LAPD experiments presented in this paper. Higher fidelity tools of at least 2D will be required to give a more realistic description of the RF E fields and the effect of the ponderomotive force on the LAPD.
Barnett, R. L., et al. "Ponderomotive force driven density modifications parallel to B on the LAPD." Physics of Plasmas, vol. 29, no. 4, Apr. 2022. https://doi.org/10.1063/5.0071162
Barnett, R. L., Green, D. L., Waters, C. L., Lore, J. D., Smithe, D. N., Myra, J. R., Lau, C., Van Compernolle, B., & Vincena, S. (2022). Ponderomotive force driven density modifications parallel to B on the LAPD. Physics of Plasmas, 29(4). https://doi.org/10.1063/5.0071162
Barnett, R. L., Green, D. L., Waters, C. L., et al., "Ponderomotive force driven density modifications parallel to B on the LAPD," Physics of Plasmas 29, no. 4 (2022), https://doi.org/10.1063/5.0071162
@article{osti_2567859,
author = {Barnett, R. L. and Green, D. L. and Waters, C. L. and Lore, J. D. and Smithe, D. N. and Myra, J. R. and Lau, C. and Van Compernolle, B. and Vincena, S.},
title = {Ponderomotive force driven density modifications parallel to B on the LAPD},
annote = {The ponderomotive force has previously been identified as a possible driver of observed density modifications close to radio frequency actuators during operation. This nonlinear force redistributes density in regions of gradients in the magnitude of an oscillating electric field and describes the influence of the fast time scale RF wave dynamics on slow time scale plasma transport. Depletion of the saturation current (a proxy for the density) measured at the Large Plasma Device (LAPD) was 30–35% during ion cyclotron range of frequencies operation. A coupled 1D plasma transport and cold plasma frequency domain wave solver was developed to self-consistently describe ponderomotive effects and was used to compare with results obtained from the LAPD experiment. The scaled current density driver for the wave model yielded an RF B field in close agreement with two components of the experimental data. However, the 1D parallel model did not accurately reproduce the amplitude or spatial distribution observed in experimental measurements of By. Within the limitations of the 1D model, initial simulation results showed that the ponderomotive force depleted up to 8% for high power (1 MW) and around 1% for the experimental power of 120 kW. This could suggest that the ponderomotive force is not the main driver of density modification for the LAPD experiments presented in this paper. Higher fidelity tools of at least 2D will be required to give a more realistic description of the RF E fields and the effect of the ponderomotive force on the LAPD.},
doi = {10.1063/5.0071162},
url = {https://www.osti.gov/biblio/2567859},
journal = {Physics of Plasmas},
issn = {ISSN 1070-664X},
number = {4},
volume = {29},
place = {United States},
publisher = {American Institute of Physics},
year = {2022},
month = {04}}
THE 6TH INTERNATIONAL CONFERENCE ON BIOLOGICAL SCIENCE ICBS 2019: “Biodiversity as a Cornerstone for Embracing Future Humanity”, AIP Conference Proceedingshttps://doi.org/10.1063/5.0013578