Diagnosing electric and magnetic fields in laser-driven coil targets
ORAL
Abstract
Laser-driven capacitor coils are widely used to generate intense magnetic fields for various applications in high-energy-density physics research. Accurate measurement of the magnetic fields is essential but challenging, due to the overlapping contributions from magnetic and electric fields in proton radiography, which is the primary tool diagnosing the field generation around the coils. In this study, we systematically analyze proton radiographs obtained from laser-driven capacitor-coil targets along two orthogonal axes under various electromagnetic field conditions, including magnetic field only, electric field only, and combined electromagnetic fields. By analyzing key features in the radiographs, we distinguish and characterize the respective contributions from magnetic and electric fields. Using detailed simulations validated by experimental benchmarks, methods to isolate and quantify the magnetic field and electric field are given. These methods enable the determination of electric current and charge distribution in a short-pulse laser-driven double-coil configuration. We measure coil current of 120 ± 10 kA, generating magnetic fields of 200 ± 20 T at the coil center—setting a new record for magnetic field generation using short-pulse-powered capacitor-coil targets.
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Publication: [1] Y. Zhang, L. Gao, H. Ji, B. Russell, G. Pomraning, J. Griff-McMahon, S. Klein, C. Kuranz, M. Wei, Determining Magnetic and Electric Field Generations in Laser-Driven Coil Targets (Submitted to Plasma Physics and Controlled Fusion, https://arxiv.org/abs/2505.02326)<br>[2] L. Gao, Y. Zhang, H. Ji, B. Russell, G. Pomraning, J. Griff-McMahon, S. Klein, C. Kuranz, M. Wei, Record Magnetic Field Generation by Laser-Driven Capacitor-Coil Targets (Submitted to Applied Physics Letters, https://arxiv.org/abs/2505.02332)
