Diagnosing current losses in the MJOLNIR DPF*

A dense plasma focus (DPF) is a compact coaxial plasma gun which completes its discharge as a z-pinch.  At LLNL the MJOLNIR (MegaJOuLe Neutron Imaging Radiography) DPF is designed for radiography and high yield operations.  This device has achieved neutron yields up to 3E11 neutrons/pulse at 2.2 MA pinch current while operating at up to 1 MJ of stored energy.  The experiments run on MJONILR are complemented by unique particle-in-cell simulations of the DPF discharges.  These detailed simulations show a mismatch between the simulated and measured currents, suggesting that current loses are occurring somewhere in the DPF head.  In order to determine if, and where, current is being lost a set of B-dot probes and Rogowski coils have been developed.  Both the probe designs and preliminary results from this set of new diagnostics will be presented.