Abstract: An ion generating apparatus utilizing a vacuum chamber with an anode and multiple, selectively operable, cathodes in the chamber. The vacuum chamber is grounded and all but the cathode or cathodes selected for use are grounded to the chamber. The anode is a high-transparency screen, preferably formed from a copper alloy. The cathodes are preferably arranged in a generally circular array, parallel to each other, so that any can be fired by a single trigger cathode assembly positioned adjacent to the array. A linear feed mechanism for moving any cathode toward the anode as cathode material is consumed may be provided.

Abstract: Disclosed is a method for detecting propagating normal zones in a superconducting coil or magnet by monitoring the energy consumed by the magnet/coil per unit time and comparing that value with a previously recorded or stored value of energy consumed per unit time. The monitoring is done outside the cryostat and external quench detection circuitry configurations are disclosed for carrying out the method.