Abstract: An automated storage and retrieval system includes a first independently operable section having a first number of predetermined storage and retrieval transactions, and a second independently operable section in communication with the first independently operable section and having a second number of predetermined storage and retrieval transactions. The first and second independently operable sections are configured to provide a respective number of predetermined storage and retrieval transactions so that the first number of predetermined storage and retrieval transactions substantially matches the second number of predetermined storage and retrieval transactions.

Abstract: An ion source including a chamber housing defining an ion source chamber and including an extraction plate on a front side thereof, the extraction plate having an extraction aperture formed therein, and a tubular cathode disposed within the ion source chamber and having an opening formed in a front half thereof nearest the extraction aperture, wherein a rear half of the tubular cathode furthest from the extraction aperture is closed.