| 摘要 |
PURPOSE:To make it possible to monitor the incident ion beam of small incident beam energy, by mounting a secondary-electron multiplying microchannel plate MCP, a secondary-electron acceleration transparent electrode with a fluorescent substance film and a light emitting state observing window. CONSTITUTION:MCP12 and a transparent electrode 14 having a fluorescent substance film 13, for example, a ZnS film formed to the surface thereof are arranged in a vacuum container 11 in parallel and a power source 15 is con nected to MCP12 while an electron acceleration power source 16 to the electrode 14 and an observing window 17 is provided to the container 11. For example, voltage of about 1kV is applied to the power source 15 and voltage of about 2-4kV to the power source 16. When an ion or neutron particle is incident to the container 11 under this condition, secondary-electron multiplication reaches about 10<3> times by MCP12 and the secondary-electron is subsequently further accelerated by the power source 16 to be incident to the film 13 of the electrode 14 to allow the fluorescent substance to emit light. By this method, the light emitting state of the film 13 can be visually observed and the beam state of a small amount of weak ion particles can be visually observed.
|
