Analysis and specification of the performances of the new JET amplifier for the vertical stabilisation

A new 25 MW power amplifier based on GTO invertors has been procured to cope with configurations of the JET plasma characterised by high growth rates of the vertical instability. The analysis of the future JET configurations, including a new set of four divertor field coils, resulted in the specification of the required performances of the amplifier and led to the choice of the technical solution. The new amplifier has now been fully commissioned on a dummy load at the JET site.