ARCHER2 Calendar May 2025

Pulsed-power driven magnetic reconnection

Dr Nikita Chaturvedi, Department of Physics, Imperial College London

Magnetic reconnection occurs when anti-parallel magnetic field lines undergo a rapid change in topology. This is thought to occur in the collisional, radiative regime in black hole accretion disks. This simulation is of 'exploding wire arrays' driven by Z, the world's largest pulsed-power facility, used to recreate astrophysical conditions in the laboratory. An immense, fast rising current (26 million amperes in 300 nanoseconds) is passed through a cage of wires, which rapidly heat and form a surface plasma that is accelerated towards plasma from an adjacent array. The ablation streams carry azimuthal magnetic fields, enabling reconnection to occur in the interaction region. The central slice through the simulation shows plasmoids (flux-ropes) forming in the reconnection region that go MHD unstable and are advected with the outflows. This simulation was performed using the CHIMERA radiation-magnetohydrodynamics code with 4 billion computational cells across 16,000 cores on ARCHER2.

This image was published on the May page of the ARCHER2 2025 printed calendar.