ELECTRON BEAM DETECTING DEVICE

摘要

An electron beam detecting device detects a state of an electron beam radiated by an electron beam radiation device. A plurality of wire electrodes, which are conductors, are disposed corresponding to a plurality of filaments, the wire electrodes being electrically insulated from each other, in the area in which the electron beams are radiated. The electrical current flowing through each of the wire electrodes is measured by an electric current measuring instrument (measuring unit). A CPU (determining unit) determines the radiation level of the electron beams by receiving a signal output by the electric current measuring instrument. The CPU judges that when the measuring instrument measures a decrease of the current value, an abnormal condition exists in the filament corresponding to the conductor with the lower current value.

主权项

1. An electron beam detecting device, by which a state of an electron beam radiated by an electron beam radiation device is detected, said electron beam detecting device comprising:
a plurality of conductors disposed corresponding to a plurality of filaments that are provided in the electron beam radiation device to radiate thermal electrons, the conductors being electrically insulated from each other, in the area in which the electron beams are radiated; a measuring unit measuring the current value flowing through each of the conductors; and a determining unit determining the radiation level of the electron beams by receiving a signal output by the measuring unit, the determining unit judging that when the measuring unit measures a decrease in the electrical current value, an abnormal condition exists in the filament corresponding to the conductor in which the lower current value is detected.