Complex sentence: ZETA remained the largest toroidal machine in the world for some time, and went on to have a very productive career for just over a decade, but in spite of its later successes ZETA was always known as an example of British folly.
Split into simpler sentences: ZETA remained the largest toroidal machine in the world for some time. But in spite of later successes, ZETA was always known as an example of British folly.