In February two big government fusion efforts announced advances (see Feb22 report) while in March it was the turn of two private companies. HB11, an Australian start-up working, like LPPFusion, to develop fusion using pB11(hydrogen boron) fuel announced that they had achieved a fusion yield of at least 0.2 J from a hydrogen-boron target hit with a PW (peta-watt) laser beam in an experiment performed at Osaka University’s Institute of Laser Engineering. So far, HB11 is the only fusion company actually using hydrogen boron fuel in experiments (LPPFusion expects to begin pB11 experiments this year). The new result is a new record for this fuel.
In the experiment, the solid target consisted of boron nitride, which had a few percent hydrogen included during the manufacturing process. The powerful LFEX laser used 6.5 MJ of electrical energy to produce a 1.5kJ laser pulse, delivered in only 2.2 ps (trillionths of a second). The laser causes electrons to accelerate much more quickly than the heavier, slower moving ions, creating a huge electrical field. The field accelerates a beam of ions, with energies up to 8 MeV (million electron volts). Some of the boron ions in the beam collide with hydrogen ions in the target, producing fusion reactions, and alpha particles (helium nuclei). The experiment was carried out by a collaboration of 16 scientists from universities in Japan, UK, France, Czech Republic and Italy, as well as Dr. Dimitri Batani from HB11.
The fusion yield is 0.03J per MJ of input to the device. By comparison, LPPFusion’s best yield with deuterium fuel is 4J per MJ, about 100 times more. The world record for deuterium fusion energy per unit input, 12 J/MJ input, is held by a dense plasma focus experiment done at the Speed-2 facility in Dusseldorf in 2001. Using the more reactive deuterium-tritium fuel, the JET tokamak in the UK reported in February a much higher yield of 5900 J/MJ of energy input. LPPFusion’s experiment later this year will aim to exceed any deuterium results using pB11 in the form of decaborane vapor.
Another announcement came from UK-based First Light Fusion. This company uses a gun to accelerate a projectile at 6.5 km/s into a target of deuterium fuel. They announced that they had achieved fusion reactions for the first time with their approach, recoding a total of 50 neutrons. The energy input to the device, in the form of gunpowder to drive the gun, is 9MJ. By comparison LPPFusion’s best results have produced 5 billion times more fusion reactions from 150 times less input energy. First Light Fusion’s result were reported in leading UK newspapers. We hope our new results will get some of the same coverage!