When a moderately intense, few-picosecond-long laser pulse ionizes gas to produce an underdense plasma column, a linear relativistic plasma wave or wake can be excited by the self-modulation instability that may prove useful for multi-bunch acceleration of externally injected electrons or positrons to high energies in a short distance. At the same time, due to the anisotropic temperature distributions of the ionized plasma electrons, the Weibel instability can self-generate magnetic fields throughout such a plasma on a few picoseconds timescale that can persist even longer than the lifetime of the wake. In the present paper, we first show using simulations that both these effects do indeed co-exist in space and time in the plasma. Using our simulations, we make preliminary estimates of the contribution to the transverse emittance growth of an externally injected beam due to the Weibel magnetic fields in a few-millimeter-long plasma. We then present the results of an experiment that has allowed us to measure the spatiotemporal evolution of the magnetic fields using an ultrashort relativistic electron probe beam. Both the topology and the lifetime of the Weibel instability induced magnetic fields in the experiment are in reasonable agreement with the fields induced by the Weibel instability in the simulations.
Wu, Yipeng, et al. "Thermal Weibel instability induced magnetic fields co-exist with linear wakes in laser-ionized plasmas." Physics of Plasmas, vol. 31, no. 7, Jul. 2024. https://doi.org/10.1063/5.0207697
Wu, Yipeng, Farrell, Audrey, Sinclair, Mitchell, et al., "Thermal Weibel instability induced magnetic fields co-exist with linear wakes in laser-ionized plasmas," Physics of Plasmas 31, no. 7 (2024), https://doi.org/10.1063/5.0207697
@article{osti_2567720,
author = {Wu, Yipeng and Farrell, Audrey and Sinclair, Mitchell and Zhang, Chaojie and Petrushina, Irina and Vafaei-Najafabadi, Navid and Babzien, Marcus and Li, William and Pogorelsky, Igor and Polyanskiy, Mikhail and others},
title = {Thermal Weibel instability induced magnetic fields co-exist with linear wakes in laser-ionized plasmas},
annote = {When a moderately intense, few-picosecond-long laser pulse ionizes gas to produce an underdense plasma column, a linear relativistic plasma wave or wake can be excited by the self-modulation instability that may prove useful for multi-bunch acceleration of externally injected electrons or positrons to high energies in a short distance. At the same time, due to the anisotropic temperature distributions of the ionized plasma electrons, the Weibel instability can self-generate magnetic fields throughout such a plasma on a few picoseconds timescale that can persist even longer than the lifetime of the wake. In the present paper, we first show using simulations that both these effects do indeed co-exist in space and time in the plasma. Using our simulations, we make preliminary estimates of the contribution to the transverse emittance growth of an externally injected beam due to the Weibel magnetic fields in a few-millimeter-long plasma. We then present the results of an experiment that has allowed us to measure the spatiotemporal evolution of the magnetic fields using an ultrashort relativistic electron probe beam. Both the topology and the lifetime of the Weibel instability induced magnetic fields in the experiment are in reasonable agreement with the fields induced by the Weibel instability in the simulations.},
doi = {10.1063/5.0207697},
url = {https://www.osti.gov/biblio/2567720},
journal = {Physics of Plasmas},
issn = {ISSN 1070-664X},
number = {7},
volume = {31},
place = {United States},
publisher = {American Institute of Physics},
year = {2024},
month = {07}}
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 584, Issue 1https://doi.org/10.1016/j.nima.2007.09.053