| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a cathode structure which avoids an increase in the power consumed by a heater, by reducing the amount of undesired heat radiation from a cathode sleeve and the amount of undesired heat conducted from the cathode sleeve to the outside of the cathode sleeve. SOLUTION: A cathode structure, having a cylindrical cathode sleeve 1 made of a high-melting-point metal, a hat-shaped cathode base 2 made of a high- melting-point metal and securely attached to one end of the cylindrical cathode sleeve 1, an electron emitter layer 3 formed to coat the top surface of the hat-shaped cathode base 2, a heater 4 enclosed in the cylindrical cathode sleeve, a cylindrical holder 5 placed on the outer periphery of the cylindrical cathode sleeve 1 in such a way as to be concentric with respect to the cathode sleeve 1, and disc-shaped support 6 supporting the other end of the cylindrical cathode sleeve 1 within the cylindrical holder 5, has a plurality of window parts 9A, 9B, 10A, 10B provided in the side face of the cylindrical cathode sleeve 1 along the longitudinal direction of the cathode sleeve 1.</p> |
