A voltage divider is connected between the negative side or cathode and ground and an intermediate point on {TAIL ~ the divider} is connected to a focusing electrode in {HEAD ~ the x ray tube} for providing a focusing bias voltage 
A voltage divider is connected between the negative side or cathode and ground and an intermediate point on { TAIL ~ the divider } is connected to a focusing electrode in { HEAD ~ the x ray tube } for providing a focusing bias voltage
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH