FYI, The onion design has been temporarily shelved. The current thinking is that it will be more difficult to manufacture than a simple cylinder shape. Look at the picture Rez’ has posted on the topic titled “Dense Plasma Focus (DPF)” on the home page. It’s a small picture but it depicts a cylinder design. Perhaps later generations of the device can have an onion design, which may well prove to be lighter and more efficient.
Meanwhile, maybe we can harass Rezwan into posting a bigger picture of this variant.