James Benford a space engineer who worked on the problem of trying to use fusion for space propulsion indicates in comments related to project Daedalus
The Daedalus concept was based on the electron-beam-driven inertial confinement fusion (ICF) concept introduced by Friedhart Winterberg around 1970 and peaked around the time of the BIS study. That means it didn’t last long. The reasons were primarily fuel pre-heat, but there were others. The successor concept, ion beam-driven ICF, lasted much longer, until the imploded wire Z-pinch succeeded in producing radiation powers so high they can, if scaled, produce implosion of a ‘pill’ of D-T to produce fusion. It now competes with lasers (the NIF). By any measure of technical merit, the Z-pinch should win out. For fusioneers, this is nostalgic; Z’s were the first fusion concept (the gas discharge type) and now the wire version is likely to succeed, far more likely than the behemoth Tokamaks (the ITER).
Minimag orion work with z-pinches for space propulsion