This cathode is available in both the modular construction (shown in the photograph) and in other constructions. It is used in a wide range of applications in all types of cathode ray tubes (CRT). This cathode has been recently developed in conjunction with UK universities and it has a significantly improved performance compared to the standard oxide cathode. It can be used in areas where previously an impregnated cathode was the only alternative.

It has the following key features :

• Allows smaller spot size (higher resolution) for wide-screen, real flat colour picture tube and projection TV applications. It handles much higher current densities (typically up to 3.5 A/cm2) than conventional oxide cathodes allowing narrower electron beams
• More stable emission characteristics and longer lifetimes than conventional oxide cathodes (>20,000 hours) at present day cathode loadings.
• Fast warm up time because of the suspended cathode structure with excellent thermal stability
• Low power consumption (0.65 W) with advanced design.
• Improved quality control and production yield because of the modular structure incorporating an integrated heater which allows simple mounting into an electron gun
• A cost effective alternative to Impregnated cathodes for many applications

Lifetime performance

The Cermet cathode shows a much smaller decrease in emission current over life than the standard oxide cathode, even at higher current loads, as shown in the graph below.  This allows this cathode to be used in higher-end CRT applications.