A liquid helium cooled finger for the Siemens electron microscope

Abstract

A liquid helium cooled finger has been fabricated to fit axially inside the standard Siemens cold finger. The apparatus has been used to examine a thinned copper transmission sample at a temperature below 29° K using a total liquid helium consumption of ten litres per hour. The temperature was determined by condensing Xe, Kr, Ar or N2 on to the cold sample during observation.