The velocity of the fast neutrons driving the chain reaction is close to the speed of light, so that would be the detonation velocity. I doubt the
velocity is related to the pressure like in conventional explosives though. The antimatter-matter annihilation on the other hand is not a chain
reaction so it's hard to define a detonation velocity. The reaction can only proceed in the boundary layer.
Regarding the rocket:
No rocket engine is strong enough to withstand a high explosive. So the propellant has to burn and not detonate. Now, a good rocket contains lots of
stored energy per dry weight which requires high energy density. Conventional bipropellants like liquid hydrogen/liquid oxygen easily store twice as
much energy per weight as high explosives. The propellant also needs to have good efficiency, which requires light exhaust gases. Water and hydrogen
are good, nitrogen and carbon dioxide from HEs are bad. Acceleration is just a matter of thrust-to-weight ratio and has little to do with the fuel
used. The interceptor missiles probably used some kind of APCP but had a huge internal surface area to burn it as quickly as possible.
|
