
Hollow secondary?
While reading the post about "odd Intellipedia caption", I noticed something in the picture that was indeed 'odd' to me - the section labeled as 'spark plug' was hollow.
Part of the picture in question:
I remember reading the spark plugs described as 'rods of plutonium' and I assumed that meant a solid chunk of metal instead of a tube. But after some thought, it made sense, since the desired effect is to produce neutrons at the moment of maximum compression.
But that led me to this question: would there be any benefit from making the whole secondary a hollow tube, with a hole in the middle (filled with the same interstage material as the rest of the casing), 2 tampers/pushers (one outer and one inner) to achieve 'double, or inward-outward' compression of the fuel in between?
If we use the picture above, the spark plug would be replaced by somewhat larger/thicker U-238 tube, and the tube would be opened on both ends.
EDIT: to make it clearer what I mean - trigger ablation of both tampers at the same time to send them against each other, compressing the fuel in between.