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arXiv · 2510.09437

Long Living Hot and Dense Plasma from Relativistic Laser-Nanowire Array Interaction

Ehsan Eftekhari-Zadeh·Mikhail Gyrdymov·Parysatis Tavana·Robert Loetzsch·Ingo Uschmann·Thomas Siefke·Thomas Käsebier·Uwe Zeitner·Adriana Szeghalmi·Alexander Pukhov·Dmitri Serebryakov·Evgeni Nerush·Igor Kostyukov·Olga Rosmej·Christian Spielmann·Daniil Kartashov
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Abstract

Long-living, hot and dense plasmas generated by ultra-intense laser beams are of critical importance for laser-driven nuclear physics, bright hard X-ray sources, and laboratory astrophysics. We report the experimental observation of plasmas with nanosecond-scale lifetimes, near-solid density, and keV-level temperatures, produced by irradiating periodic arrays of composite nanowires with ultra-high contrast, relativistically intense femtosecond laser pulses. Jet-like plasma structures extending up to 1~mm from the nanowire surface were observed, emitting K-shell radiation from He-like Ti$^{20+}$ ions. High-resolution X-ray spectra were analyzed using 3D Particle-in-Cell (PIC) simulations of the laser-plasma interaction combined with collisional--radiative modeling (FLYCHK). The results indicate that the jets consist of plasma with densities of $10^{20}$-$10^{22}$ cm$^{-3}$ and keV-scale temperatures, persisting for several nanoseconds. We attribute the formation of these jets to the generation of kiloTesla-scale global magnetic fields during the laser interaction, as predicted by PIC simulations. These fields may drive long-timescale current instabilities that sustain magnetic fields of several hundred tesla, sufficient to confine hot, dense plasma over nanosecond durations.

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Ehsan Eftekhari-Zadeh, Mikhail Gyrdymov, Parysatis Tavana, Robert Loetzsch, Ingo Uschmann, Thomas Siefke, Thomas Käsebier, Uwe Zeitner, Adriana Szeghalmi, Alexander Pukhov, Dmitri Serebryakov, Evgeni Nerush, Igor Kostyukov, Olga Rosmej, Christian Spielmann, Daniil Kartashov. 2025-10-10. Long Living Hot and Dense Plasma from Relativistic Laser-Nanowire Array Interaction. https://arxiv.org/abs/2510.09437

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