UPGRADING OF THE NEUTRAL BEAM POWER SUPPLIES FROM 80KV/60A TO 140KV/60A

The present Neutral Beam Power Supplies consist of 16 units, each with a capacity of 80W/60A. Each of these units can be connected to a 80kV/60A Neutral Injector or alternatively two of these units can be connected in series giving 160kV/60A output capability. In this latter configuration two 160kV/30A Neutral injectors are connected in parallel at the output of the series connected units. In both cases the total DC output power of the Power Supplies is the same and equal to 76.8MW. In the future JET would like to increase the available neutral injection heating power for the plasma. This can be achieved by either increasing the output current of the existing power supplies or by increasing the output voltage. It is preferred to increase the voltage because this limits the increase in plasma density caused by the injected particles. The increase in voltage is obtained by connecting a new 60kV/60A power supply in series with the output of the existing unit. This paper explains the main requirements for this design and presents a reference designbased on these requirements.