John F. O’Hanlon, PhD, Emeritus Professor of Electrical and Computer Engineering at the University of Arizona, Tucson, USA and retired IBM Research Staff Member. He is a Senior Member of the IEEE, a Fellow of the AVS and has published widely on vacuum technology and related subjects. Timothy A. Gessert, PhD, is Principal Scientist and Managing Member of Gessert Consulting, LLC, USA, former Principal Scientist at the National Renewable Energy Laboratory, USA, and Fellow and Past President of the AVS. He has published extensively on vacuum technology and related subjects.