STABILITY OF HIGH-CURRENT DENSITY MAGNETS WITH NARROW LIQUID-HELIUM CHANNEL COOLING

To overcome the low threshold against disturbance usually observed in high current density, close-packed magnets, it was proposed to introduce narrow liquid helium channel cooling into the winding. Several magnets with winding inner diameters ranging from 8 to 60 cm were constructed and tested. The small magnets show quite good performance, but the 60 cm solenoid shows quite serious training and degradation. The experimental results are summarized and some analysis and discussion are given.