レーザー光走査法によるNEA活性化過程の観察
1980 年 49 巻 1 号 p. 23-28
詳細
1980 年 49 巻 1 号 p. 23-28
It is well known that electron emission properties of negative electron affinity (NEA) surface depend upon the cleanliness of the surface to an atomic level as well as its activation treatment with caesium and oxygen.
Observations are reported on photoemission images of the activated surface in Si and GaAsP cold cathode, obtained by scanning the surface with He-Ne laser spot. It was found that the optimum activation procedure for photoemission from the cleaned area is not consistent with that from the uncleaned surrounding area and was also shown that the optimum activation condition for the cold cathode emission corresponds to that of the optimum photoemission from the active section of the cold cathode.
Finally, we demonstrate that these observations are useful for the evaluation of activation process of the NEA cathode. Resolution of the photoemission images was about 10 Am and was limited by the size of the laser beam spot.
