The anodes of all of the extraction diodes are connected together at a common anode contact, and a voltage is applied across the extraction diodes by connecting {HEAD ~ a voltage source} to {TAIL ~ the common anode contact} so that the extraction diodes are reversed biased and thus block current flow 
to
The anodes of all of the extraction diodes are connected together at a common anode contact , and a voltage is applied across the extraction diodes by connecting { HEAD ~ a voltage source } to { TAIL ~ the common anode contact } so that the extraction diodes are reversed biased and thus block current flow
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH