Crt cathode meterial

[Electronic M]

The getter is a reactive metal like magnesium....I hear some (home made radio tube) experimenters have taken ones from junk tubes and re-flashed them with RF induction heating rigs.

They coated the cathodes with some mix of the emissive material and another substance that prevents it from reacting with air (do some searches on vacuum tube and CRT making for the recipe). The stabilizer is burned off a during the final stages of evacuation or after IIRC.