SEARCH Articles Figures Tables Discharge source and drift tube assembly used by Inomata and co-workers , The primary discharge region consists of elements ED I-ED2 and is followed by a source drift region . Voltages are maintained along the electrode network via a potential divider using the resistors shown along the left side of the electrode chain. Reproduced with permission from , Copyright 2006 John Wiley Sons, Ltd. [Publishers Imprint]