Operation is not so difficult. High technology needed. Angular distribution is sharp, 1.6x10 -2 rad Used at high temperature Short lifetime. Point adjustment needed. Vulnerable to the thermal expansion or vibration.
Adjustment is sometimes necessary.
Very high technology needed. Tips Flat tips are recommended for applications where stability and long lifetime are the prime considerations, and where some degree of brightness can be sacrificed. Sharp Tips Sharp tips are recommended for applications where initial brightness is the foremost consideration and where shorter lifetime can be accepted. The cathodes tips are mounted between two carbon blocks and indirectly heated. These cathodes offer optimum structural stability and chip stability together with substantially longer service life.