FIELD-EMISSION OF ELECTRONS FROM GLASS TIPS WITH INTERNAL CONDUCTING COATS

A method of drawing glass micropoint emitters having an internal condu cting coat is described. The field emission characteristics of emitter s with a silverdag internal coat show a switch-on effect to a high (1 to 10 muA), stable saturation current. On lowering the voltage, the em ission current follows a Fowler-Nordheim emission equation until a thr eshold voltage is attained. A model of the emission is presented in wh ich a hot-electron emission process is in series with a large ohmic re sistor. The performance of these emitters is superior to that of previ ously described glass-coated tungsten emitters.