Charged particle acceleration experiments in a dense plasma focus driven by a high-inductance generator*

Charged particle acceleration is being investigated in a dense plasma focus (DPF) driven by the Hawk pulsed-power generator at the Naval Research Laboratory. The high inductance (607 nH) and associated high voltage (640 kV) and fast rise time (1.2 µs) of Hawk are unusual for a DPF driver, as is the initialization of the DPF using local injection of neutral gas and plasma into a vacuum chamber, rather than a conventional neutral gas fill. Neutron yields of up to 3.6×10¹⁰ at a peak current of I=670 kA have been measured using rhodium foil activation counters, significantly above the yield expected based on purely I^4.4 scaling from conventional DPFs. Evidence of deuteron and x-ray acceleration has been recorded, respectively, in ion multi-pinhole images obtained with filters of varying thickness and in the form of x-ray pinhole images of emission from the pinch and surrounding hardware. The initial conditions established by the injected gas and plasma have also been varied to accentuate the observed neutron or x-ray emission.