| 摘要 |
<p>PURPOSE:To make a cathode heater small-sized and make the heating power efficient by winding a tungsten wire upward from below along one spiral groove of a mandrel and winding it downward from above along the spiral trough section of its surface. CONSTITUTION:A molybdenum fine wire 12 is wound on the outer periphery of a tungsten wire 11, which is wound upward from below along the spiral groove 21 of a mandrel 2. The winding direction is changed along the groove 22 at the top section, and the tungsten wire 11 is wound downward from above along the spiral trough portion formed between the wire 1 previously wound upward from below on the mandrel 2 on the wire 1. Subsequently stress distortion is removed by heat treatment, then the molybdenum fine wire 12 closely wound on the outer periphery of the tungsten wire 11 is solved and removed. The winding pitch is narrow, a heater is made small-sized, and the efficiency of the heating power can be improved.</p> |
