| 摘要 |
<p>PURPOSE:To obtain a getter with good quality from which a great amount of barium is emitted and in which splash or peeling is minimally caused by packing a getter case with a getter pellet the density of which increases from its bottom to its surface. CONSTITUTION:An under jig consists of a main section 12 and a movable section 13 which forms an annular groove 14. After a first portion of a getter powder 211 is homogeneously packed in the groove 14, an upper jig 15 is used to form a first layer 21 by compression. Then a second portion of the getter powder 211 is homogeneously packed on the first layer 21 and a second layer 22 is formed by compression. After that, a third portion of the getter powder 211 is homogeneously packed on the second layer 22 and a third layer 23 is formed by compression, thereby making a getter pellet 24 consisting of the first, the second and the third layers 21, 22 and 23 arranged in order of decreasing density. Next, after an annular metallic getter case 32 with a U-shaped cross section is placed in such a manner as to cause its opening 321 to face the getter pellet 24, the getter pellet 24 is packed into the getter case 32 by moving the movable section 13 in the direction indicated by the arrow.</p> |
