The Current Extractions Channel of the Nevis Synchrocyclotron Conversion Project

A current channel has been designed (computer) with a total septum thickness including supports of 0.150 in. It provides a field jump of over 6 kG and a gradient of over 1.5 kG/in. The direction of the gradient is such that the channel field superimposed on the fringing field of the cyclotron magnet produces a radially focusing field. The heat load and the power dissipation in the septum will be greatly reduced by having the septum flare out from 0.125 in. at the upstream end of the channel to about 0.600 in. at the downstream end. This reduces the power consumption in the septum to 40 kW.