| 摘要 |
PURPOSE:To suppress the occurrence of secondary photoelectrons from a grid electrode receiving the light reflected by a sample. CONSTITUTION:A carbon perfluoride derivative or a silicone derivative is coated on the surface of a grid electrode 15 arranged near the opening section of a cathode to form a film 16 with large work function on the surface. The photoelectrons emitted from the grid electrode 15 when the reflected light from a sample is received are attenuated with the kinetic energy by the film 16, can not jump out to the outside, and do not contribute to the electric discharge at an anode. Only the photoelectrons emitted from the sample contribute to the electric discharge at the anode, and correct measurement can be performed. |
