A new paper published Feb 21 in Nature Communications (junior sibling publication to the more prominent Nature) has given widespread publicity to the advantages of hydrogen-boron (pB11) fusion fuel. While LPPFusion has long explained such advantages, as have other companies like TAE Technologies and HB11, the dominant narrative in fusion has been the prominence of DTÂ fuel. This new paper, which was highlighted in many media outlets, emphasized that pB11 is not only a viable route to fusion, capable of net energy production, but greatly simplifies the design of fusion generators by eliminating destructive neutron emission.
The paper, authored by researchers form TAE Technologies, University of California-Irvine and the National Institute for Fusion Science, report on pB11 fusion experiments in the Large Helical Device, a 25 year-old stellarator operating in Toki, Japan. A stellarator is a fusion device that is close in concept to the better known tokamaks. It uses a complex twisting external magnetic field to trap plasma at low density (Fig. 1).  The experimenters injected boron dust into the stellarator, building up a dilute boron plasma . Then they turned on the hydrogen ion beams already built into the LHD. These beams supplied protons at an energy of 135-180 keV, hot enough to achieve pB11 fusion. The beams had sufficient current, abut 13 A, to heat the dilute plasma to high temperature.
The researchers counted the alpha particle (helium nuclei) produced from the pB11 reactions and observed a fusion power yield of about 5 W during the 2-second runs. This yield implied that the hot pB11 ions were confined for tens of thousands of orbits around the toroidal stellarator and that perhaps 1 in a million burned in the fusion reactions. This was a significant achievement as the previous pB11 fusion experiments had been done using laser facilities with inertial confinement—the plasma confined only by its own inertia.
By comparison, the stellarator experiments achieved a fusion output to device  energy input ratio of 0.012 J per MJ, a bit short of the 0.05 J per MJ ratio achieved in the laser experiments. Using the much less reactive deuterium fuel, LPPFusion has achieved the much higher ratio of 4 J per MJ and we expect to do still better with pB11 in the near future. But the new experiments and relatively high profile media coverage gives a boost in credibility to all work with pB11 fuel.

Figure 1. The LHD stellarator in Loki Japan trapped a dilute boron plasma (yellow band, left) in complex magnetic fields and then shot beams of protons into the plasma. Fusion reactions generated alpha particles (green lines on right) which were counted by a detector (bottom, right). Figure in the paper.
Stay tuned for Part 2 of this Special report, coming tomorrow.