Apologies Vanadium 50, it seems there’s more to spallation than my first enquiries showed. I’m guessing stray protons could chip neutrons from surrounding materials and deposit them elsewhere. As I’ve stated before I’m no physicist.
Still hoping for a reply to the ‘long spacecraft ’...
Thanks very much for your replies Astronuc and Va 50 (and Joskoplas, of course).
To summarize (please correct me if I’m wrong):
Electrons + positrons -> gamma rays
Protons + antiprotons -> pions -> muons -> gamma rays
So no residual radiation. Spallation, as the name suggests, would lead to...
Okay I've done some more searching (would have been far more sensible to do this before I wrote it). I'm no physicist & the story's theme is resource depletion. Gamma rays are all you get? So much for an Orion like spacecraft . However I have found mention of "pions and other charged particles"...
Thanks for your prompt answer Joskoplas.
It's my understanding that the blast cone need not reflect gamma emissions per se, simply redirect thrust. I'm hoping the gamma rays (or any another product resulting from an antimatter reaction) will interact to some extent with the blast cone/ engine...
I've written a SF story where a twenty million ton metallic asteroid is moved by antimatter propulsion. Apparently antimatter engines emit gamma rays. At the moment I'm planning to stick to pure antiproton annihilation 'cause it's easier to explain (so not a hybrid engine). For plot purposes...