At LPPFusion, we’re using the hot, dense plasmoid produced by our dense plasma focus (DPF) device to fuse hydrogen-boron fuel. But two other DPF groups are taking different approaches to fusing hydrogen-boron or pB11. Both use solid boron targets, onto decaborane gas, as LPPFusion does. The group in Krakow, Poland uses a laser to vaporize the boron at just the moment that a hydrogen current sheath converged on the same spot. They have not yet reported results. The group using DPFs in Warsaw and Swierk, Poland hits the solid boron target with a hydrogen beam emitted by the DPF plasmoid. This group now has published their first results with some boron fusion detected, although not a lot. After much effort over years to get the target to survive in high energy environment of the DPF, the group placed the target 20 cm from the tip of the anode in the Swierk DF-360 device, which has a radius of 6 cm (a bit more than double the size of FF-2B’s anode.) They measured about 400 alpha particles/cm2 at right angles to the proton beam. While the authors of the paper declined to estimate the total fusion production, something of the order of 10,000 reactions probably took place, releasing around 15 nJ of energy. This is a small amount compared with more than 0.25 J of boron fusion achieved with proton beams produced with lasers, using input energy comparable with PF-360’s input of 100 kJ. It’s possible that placing the target so close to the anode interferes with the production of the plasmoid that generate the proton beam in the DPF. However, achieving any boron fusion is an accomplishment and LPPFusion’s Lerner has congratulated our colleagues on their progress.
