EXPERIMENTAL-STUDY OF FIELD-EMISSION CHARACTERISTICS AS A FUNCTION OFTHE EMITTER TO ANODE DISTANCE

It was obtained experimentally that the fluctuation of the held emissi on current was increased as the anode was approached to the emitter, u nder a low level of the vacuum condition. It is numerically solved tha t the number of generated gas molecules and ions by electron stimulate d desorption on the anode surface come to the emitter surface. Under u ltrahigh vacuum, the number was not so different for the distance. On the other hand, under low level vacuum condition, the number was incre ased largely as the anode approached the emitter. So the fluctuation c an be increased when the anode approaches the emitter under low level vacuum condition. (C) 1998 American Vacuum Society.