| 摘要 |
PURPOSE:To increase the dielectric withstand voltage of a charged particle ray device such as an electron microscope by interposing EP rubber between a bushing formed using an epoxy resin and a replacement bar formed using the same resin when attaching an electron gun or similar equipment, to which high voltage is applied, to the device. CONSTITUTION:When holding an electron gun 3 to which high voltage is applied within the mirror tube 1 of a charged particle ray device such as an electron microscope, a funnel-like bushing 19 formed by integrating end members 20 and 21 having field-alleviating rings 15 and 16 with an epoxy resin is fixed between the mirror tube 1 and the electron gun 3. At the same time, a funnel-like insulating replacement bar 22 formed by unifying an epoxy resin, a lid 12 and the electron gun 3 is attached to the bushing 19 with an insulating spacer 23 made of EP rubber interposed, thereby completing assembly. As a result, it is possible to achieve a high degree of close contact between the replacement bar 22 and the bushing 19 even when the accuracy of the bar 22 and the taper of the bushing 19 is somewhat low. Accordingly, it is possible to easily perform the replacement of the electron gun 3 or similar equipment by producing a high dielectric withstand voltage. |
