Outside Influences

Each Caen mainframe has an Interlock input on the front panel which may be used to disable high voltage output unless desired external conditions are satisfied. For example, if the gas system is in alarm the wire chamber high voltage will be shut off. Because they share a common crate, the high voltage supplies for both the HMS Gas erenkov counter and the HMS drift chambers will be disabled. If you discover that you cannot get certain high voltage channels to come up, try to find out if they are interlocked.