PREVENTIVE DEVICE AGAINST CONTAMINATION ON ELECTRON OPTICS EQUIPMENT

摘要

PURPOSE:To keep clean a part on which the contamination is apt to occur by keeping the part at a predetermined temperature or higher. CONSTITUTION:An iris diaphragm 4 is kept clean of contamination by heating it to a predetermined temperature, for example 500 deg.C. A driver 10 operates responding to a temperature detected by thermo-sensor 9, and a heater 11 is controlled at the determined temperature by the driver 10. The heat is transmitted quickly to a jig 3 and the iris diaphragm 4 through a heat pipe 1 for heating, and heats the instrument 3 and the iris diaphragm 4 to the predetermined temperature.