Getter for use in evacuated tube envelopes

摘要

An evacuated tube (24) includes an envelope (50) and an electrode (78) in the tube envelope (50). The electrode (78) is electrically connected to conductors (74a, 74b) that extend through the tube envelope (50). A getter (72) is included in the tube envelope (50) and is electrically connected to the conductors (74a, 74b) extending through the tube envelope (50). Diodes (82a, 82b) are connected to the electrode (78) and the getter (72) for selectively providing electrical energy through the conductors (74a, 74b) extending through the tube envelope (50) to one of the electrode (78) and the getter (72).