The Kimball Physics Lanthanum Hexaboride Cathode (LaB6) is a high performance, resistively heated, thermionic electron source. It is currently employed in many brightness-limited electron optical systems: SEM’s, TEM’s, probes, electron lithography systems, and more.
It is based on a well-proven heater structure, which has recently been further refined with features that include improved reliability of the heater circuit, improved stability of the LaB6 crystal, and less exposure of LaB6 to reduce Wehnelt aperture contamination.
With the ES-423E (Extended Life) LaB6 Crystal, lifetimes in excess of 6 months of continuous operation are regularly achieved in commercial SEM’s and TEM’s with suitable gun vacuum.