Abstract:
PURPOSE:To interrupt operation of the captioned machine when electrical discharge is produced in an electron gun by detecting a current flowing in a circuit and voltage applied to load, and operating a high-tension interruption device in a state thereof insulated from an earth by means of optical fibers. CONSTITUTION:A high-tension main circuit of an electron beam processing machine is adapted to have a high-tension power source 1, an electron gun 2, and a high-tension interruption device 3, and adapted to interrupt operation of the electron gun 2 by making use of the high-tension interruption device 3 when electrical discharge is produced in the electron gun 2, and return it to an original state after the elapse of prescribed time for protecting the device. A control circuit 4 thereupon receives signals from a beam current detector circuit 6 disposed serially between the high-tension power source 1 and an earth and an accelerating voltage detector circuit 7 arranged parallely to the high-tension main circuit for controlling the high-tension interruption device 3 with use of optical fibers 5. Accordingly, a problem of dielectric strength of the device against the earth can be eliminated to prevent any electrical discharge form being produced in the electron gun 2 for applying the captioned machine with ease to existing processing machines.
Abstract:
PURPOSE:To decrease the cost of a charged-particle beam device, reduce a space occupied by an acceleration power supply and reduce the space of the device by using one acceleration power supply for plural electron-beam generators and enabling them to be operated simultaneously or according to the time-division system. CONSTITUTION:The cathode 31 of an electron-beam generator 38 is heated with a cathode-heating power supply 21, and a voltage for accelerating an electron beam 34 is given from an acceleration power supply 7. At the same time, the output voltage of a grid power supply 22 applied across the cathode 31 and a grid 32 is controlled so that the current of the electron beam 34 becomes a given value by detecting the current of the electron beam 34. A plural number of such electron-beam generators 38 and 111 are installed to which acceleration voltages are supplied from the acceleration power supply 7. A cathode-heating power supply 21 and a grid power supply 32 are installed in each of the plural generators 38 and 111. The quantity of the electricity of the electron beam 34 is measured by, for example, a current-measurement resistance 6 placed in a high electric potential area located in a box-like body 36.