> from almost all prior reactors (they are tokamaks)
Tokamak and Stllerator are about equally old, 1953 vs 1954, while both types where for a period developed in secrecy behind either side of the iron curtain till end of the 1960ies where collaboration started.
IPP was founded in 1960 (by, among others, my dad) and focussed on Stllerator since then (while collaborating in JET and ITER around their tokamak projects)
Apparently stellarators only became feasible recently, mostly due to vastly improved computing power, which they need to optimize the crazy shapes (https://www.ipp.mpg.de/w7x gives an idea)
(Heard that on a podcast with two of the lead physicists/engineers working there)
Yes, they are complex and require both, complex calculation and precise manufacturing and 7x is the first one being energy-positive, but tokamaks aren't really ahead either.
Tokamak and Stllerator are about equally old, 1953 vs 1954, while both types where for a period developed in secrecy behind either side of the iron curtain till end of the 1960ies where collaboration started.
IPP was founded in 1960 (by, among others, my dad) and focussed on Stllerator since then (while collaborating in JET and ITER around their tokamak projects)