  The dense plasma focus (DPF) is a classic Z-pinch plasma device that has been
studied for decades as a radiation source. The formation of the m = 0 plasma
instability during the compression phase is linked to the generation of
high-energy charged particle beams, which, when operated in deuterium, lead to
beam-target fusion reactions and the generation of neutron yield. In this
paper, we present a technique of seeding the m = 0 instability by employing a
hollow in the anode. As the plasma sheath moves along the anode's hollow
structure, a low density perturbation is formed and this creates a non-uniform
plasma column which is highly unstable. Dynamics of the low density
perturbation and preferential seeding of the m = 0 instability were studied in
detail with fully kinetic plasma simulations performed in the Large Scale
Plasma particle-in-cell code as well as with a simple snowplow model. The
simulations showed that by employing an anode geometry with appropriate inner
hollow radius, the neutron yield of the DPF is significantly improved and
low-yield shots are eliminated.
