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arXiv · 2607.06946

Ultrafast proton radiography of the magnetic fields generated by a laser-driven coil current

Lan Gao·Hantao Ji·Gennady Fiksel·William Fox·Michelle Evans·Noel Alfonso
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Abstract

Magnetic fields generated by a current flowing through a U-shaped coil connecting two copper foils were measured using ultrafast proton radiography. Two $\sim$1.25 kJ, 1-ns laser pulses propagated through laser entrance holes in the front foil, and were focused to the back foil with an intensity of $\sim$3 $\times$ 10$^{16}$ W$/$cm$^{2}$. The intense laser-solid interaction induced a high voltage between the copper foils and generated a large current in the connecting coil. The proton data show $\sim$40-50 Tesla magnetic fields at the center of the coil $\sim$3-4 ns after laser irradiation. The experiments provide significant insight for future target designs that aim to develop a powerful source of external magnetic fields for various applications in high-energy-density science.

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Lan Gao, Hantao Ji, Gennady Fiksel, William Fox, Michelle Evans, Noel Alfonso. 2026-07-08. Ultrafast proton radiography of the magnetic fields generated by a laser-driven coil current. https://doi.org/10.1063/1.4945643

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