Hi All

In Zubrin's "Entering Space" he describes an antimatter photon rocket that is basically a giant light-bulb, but the performance figures he later gives when discussing detecting a photon rocket are absurd - namely he has a photon rocket with a power output of 120 petawatts to push a million ton starship at 0.8 m/s^2 [which works] but to do so with a solid radiator at 2400 K the radiator would be almost 100 km across.

Instead I have postulated a magnetically confined U238 vortex radiating at ~ 25,000 - 50,000 K, which is the temperature range of various gas-core NTR designs. Instead of encasing it in quartz, like the NTRs, I suggest just holding it magnetically at the focus of a BIG parabolic mirror, and heating it with anti-proton beams to act as much higher efficiency photon rocket. The mirror would need to be actively cooled and a very cheap source of anti-matter found but to me it seems like a sound - if speculative - idea.

Any suggestions?

Adam

PS U238 is preferred because its atoms are heavy and hence "slow" at 25-50,000 K [RMS v ~ 1,900 m/s]. If the U238 vortex is toroidal it might be self-stable. The drive itself is powered by antimatter NOT fission.