Re:U.S. physicists rally around plan to build fusion power p...
by pfdietz on Thursday December 10, 2020 @04:47AM
(#25371813)
> Fusion should lead to unbeatable specific [impulse]
No, because the effective specific impulse is so low, as a fusion reactor will only be able to fuse a small fraction of its mass before it is too radiation damaged to work. ITER, for example, would take 300,000 years to fuse its own mass in fusion fuel, but no DT reactor could operate more than a few years (if that) before parts need replacing.
If you want high effective specific impulse and high thrust at high specific impulse, beamed power is the way to go.
No, because the effective specific impulse is so low, as a fusion reactor will only be able to fuse a small fraction of its mass before it is too radiation damaged to work. ITER, for example, would take 300,000 years to fuse its own mass in fusion fuel, but no DT reactor could operate more than a few years (if that) before parts need replacing.
If you want high effective specific impulse and high thrust at high specific impulse, beamed power is the way to go.