 The conductive shells were intended to help stabilize the plasma, but were not completely successful in any of the machines that tried it.With progress apparently stalled, in 1955 Kurchatov called an All Union conference of Soviet researchers with the ultimate aim of opening up fusion research within the USSR.In April 1956, Kurchatov travelled to the UK as part of a widely publicized visit by Nikita Khrushchev and Nikolai Bulganin.