Measuring magnetic fields in laser-driven coils with dual-axis proton deflectometry

0549030 - FZÚ 2022 RIV GB eng J - Journal Article
Bradford, P. - Dearling, A. - Ehret, M. - Antonelli, L. - Booth, N. - Carroll, D.C. - Clarke, R.J. - Glize, K. - Heathcote, R. - Khan, M. - Moody, J.D. - Pikuz, S. - Pollock, B.B. - Read, M.P. - Ryazantsev, S. - Spindloe, C. - Ridgers, C.P. - Santos, J.J. - Tikhonchuk, Vladimir - Woolsey, N.C.
Measuring magnetic fields in laser-driven coils with dual-axis proton deflectometry.
Plasma Physics and Controlled Fusion. Roč. 63, č. 8 (2021), č. článku 084008. ISSN 0741-3335. E-ISSN 1361-6587
R&D Projects: GA MŠMT LQ1606
Research Infrastructure: ELI Beamlines III - 90141
Institutional support: RVO:68378271
Keywords : magnetic fields * proton radiography
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.532, year: 2021
Method of publishing: Open access

By driving hot electrons between two metal plates connected by a wire loop, high power lasers can generate multi-tesla, quasi-static magnetic fields in miniature coil targets. Many experiments involving laser-coil targets rely on proton deflectometry directed perpendicular to the coil axis to extract a measurement of the magnetic field. In this paper, we show that quantitative measurements using perpendicular probing are complicated by the presence of GV m−1 electric fields in the target that develop on sub-ns timescales. Probing parallel to the coil axis with fiducial grids is shown to reliably separate the electric and magnetic field measurements, giving current estimates of I ≈ 5 kA in 1 mm- and 2 mm-diameter wire loops. An analytic model of proton deflection in electric and magnetic fields is used to benchmark results from the particle-in-cell code and help deconvolve the magnetic and electric field deflections. Results are used to motivate a new experimental scheme that combines a single-plate target with axial proton probing and direct current measurements.
Permanent Link: http://hdl.handle.net/11104/0325071