Effect of crystallites on surface potential variations of Au and graphite

摘要

Surfaces made of the nonreactive materials Au and graphite exhibit low surface potential variations after a lowhyphen;temperature ultrahigh vacuum bake. The variations (due to the finite size crystallites of these materials) may be reduced to a minimum by using Au surfaces of grain size less than 10 nm and graphite surfaces with highly alignedchyphen;axis orientation. Procedures where this may be accomplished are described. Application to the Los Alamos antiproton gravity experiment is presented.