High current, high brightness, single crystal
Emission current densities up to 30A/cm2
Range of emission surface sizes
Operating pressure 10-7 torr
Kimball Physics single crystal lanthanum hexaboride (LaB6) cathodes are available for most makes of electron microscopes and other electron beam instruments where a suitable gun vacuum in the region of 10-7 Torr is attainable. The filament heater can then be driven by the normal power supply of the microscope.
Brightness above 1 x 106 Amp/cm2 steradian is achievable.
For SEM applications, the higher brightness provides better imaging resolution and improved efficiency for microanalysis. For TEM, the low energy spread of the LaB6 filament is particularly advantageous for high resolution imaging. Alternatively, LaB6 filaments may be used where a long filament life is important; lifetimes in excess of six months continuous operation are regularly achieved.