Some more detail, the reactor is based on a non sustained reaction idea and being a little over a meter across would put the Skunkworks to shame with their "tiny" trailer-sized reactor they are working on, if it worked.
Two neutrons are raced around the track and then collide as femto-second laser pulses hit the same spot. The inner layer collects the waves of energy. The second is magnetic shielding and the third is secondary heat shielding if the first layer fails.
This is only half of the reactor. Lots of components used and manipulated.
The three shells for the fusion reactor based on particle acceleration.