LPPFusion Chief Scientist Eric Lerner joined more than 100 other researchers in the Fourth International Workshop on Proton-Boron Fusion held in Frascati, Italy (near Rome) Sept. 30-Oct.3. This conference was even more encouraging than the previous one held last year in Prague. Most significantly, nearly all the experimental results showed fusion yields above simulations, which is the opposite of what has been true for years for deuterium and deuterium-tritium reactions in nearly all machines.
For example, a Czech-based group got about 1.5 J of hydrogen-boron fusion energy by bombarding a solid target with a 7 J proton beam, an amazing ratio of energy out to energy in. Of course, the input proton beam was generated by a much larger laser beam, which in turn required 1.2 MJ of electric input energy. This is very far from net energy, where more energy is produced than is fed into the machine. But such a ratio of particle energy in to fusion energy out is very encouraging for LPPFusion’s own FF-2B machine, which produces accelerated and heated particles far more efficiently than a laser.
Some insight into how such great yields are produced was provided by simulations of lasers interacting with plasmas, as they do in the nano-second-pulse lasers. I. Tazes and colleagues in Crete showed in these simulations that the plasma is confined in magnetic vortices, as the LPPFusion team has long theorized, with magnetic fields up to the gigagauss levels that we are aiming for. Confined densities were about 1021/cm3. These simulations lend a great deal of credibility to LPPFusion’s calculations.
In simulation by I. Tazes and colleagues, a proton beam generated by a laser generates a powerful magnetic field on left. The blue color indicates the field direction towards the viewer and the red color away, showing that a magnetic vortex or filament is created. The density image on right, for the same simulation at the same time, which reflects what would be seen in optical images, looks like some our best plasmoid images. It shows how a fairly tangled density map can be reflective of a very ordered magnetic field as at left.
Lerner presented LPPFusion’s recent progress towards pB11 shots, including our revised predictions for pB11. He reported that if we just achieve the same plasma conditions that we had with deuterium, we’ll get a respectable 1.5 J in fusion yield and will jump to the front of the race for wall plug efficiency with pB11—25 part per million (PPM) vs about 1 PPM for the best previous results. If we meet our latest theoretical predictions, we’ll get something in the range of 10 -100 J. That approaches, but is actually less than, what we would get from just scaling up the other pB11 results to our beam power. Lerner offered to use FF-2B’s powerful ion beam to test anyone’s targets. There was a lot of interest in that and several other opportunities for collaboration, which we will report on as they develop.
LPPFusion Chief Scientist Eric Lerner presenting our results at the 4th Fourth International Workshop on Proton-Boron Fusion