X-Ray imaging of ultrafast magnetic reconnection driven by relativistic electrons

Abstract

Evidence of magnetic reconnection (MR) events driven by relativistic electrons is observed between two high-intensity laser/plasma interaction sites. The two laser foci were on average 20um FWHM containing 50TW of power each, delivered with a split f/3 paraboloid onto copper foil targets at a focused intensity of 10¹⁹ W/cm² with the HERCULES laser system. Cu K-alpha emissions from the interactions were imaged with a spherically bent Quartz crystal, and by motorizing one half of the paraboloid vertically the focal separation was varied between 0- 400um. Splitting the beam halves revealed an enhanced region between the foci with the highest a maximized K-alpha signal intensity at one inter-beam separation, evidencing inflow from relativistic electron driven MR. A filtered LANEX screen was imaged to search for outflow/jet electrons along the plane of the target surface and normal to the axis defined by the two spots, to calculate the electron temperature and to search for spatial profile nonuniformities potentially directly originating from reconnection events. Ongoing 2D and 3D PIC simulations are being conducted to better understand and model the measured electron outflow dynamics.