General fusion aims to develop an acoustically driven magnetized target fusion (MTF) reactor. Two spheromaks are made to merge in the center of a 3 meter diameter sphere full of liquid lead-lithium. 200 pneumatic pistons hit the outside of the sphere and launch an inward going spherical pressure wave that focuses and compresses the merged spheromak (or FRC) to thermonuclear condition.
We have so far built one of the two spheromak generators and achieved 40 cm outside diameter, 2E16 cm-3, 20 eV and 80 microsecond life.
Our target is 40 cm outside diameter, 1E17 cm-3, 100 eV and 100 microsecond life. We have built two pneumatic pistons.
The impact timing accuracy achieved by servo control is +/-5 microsecond. Simulation indicates that we need +/- 10 microsecond. We have successfully sent the pressure wave in liquid lead. Finally, in order to prove MTF faster without building the large and expensive sphere, we started a program with high explosive compression. Metal jetting into the collapsing chamber was observed. This might disrupt the plasma. We are changing the design of the compression chamber to address this issue.
In the next year, we are planning to collapse liquid metal cavity with 14 pistons to check the symmetry achieved. We also plan to compress in 100 microsecond with high explosive the spheromak plasma from our generator from an initial 40 cm, 1E17 cm-3, 100 eV, 100 us life to a final 4 cm, 1E20 cm-3, 10 keV, 10 us life and therefore demonstrate break-even conditions. We presently have 24 M$ in the bank and 47 employees (and still hiring) to achieve these goals.
According to company spokesman Michael Delage, the first laboratory tests of the design have gone well, achieving a temperature of 5 million degrees for 1 microsecond. It remains to be seen whether this approach can be scaled up all the way to fusion – and beyond that to break-even. “There are no magnetised plasma experiments that we are aware of at the plasma temperatures and densities necessary for net-gain fusion,” Delage says. “The only way to verify this is by experiment.” The firm has raised the $30 million it says it needs, some of it from Amazon founder Jeff Bezos