| 摘要 |
PURPOSE:To charge safely and securely a radioactive material having a short half- value period into a tube by holding a radioactive material having a special half- value period and radioactivity on an electrode, closely covering the holding part with nonradioactive material, sealing the tube including the electrode, and removing the cover by impact with electron. CONSTITUTION:A radioactive material having a short half-value period within the range from more than about 0.5 year to less than about 10 years and radioactivity of less than 100 micro curies per luminous tube is previoulsy attached to an auxiliary electrode composed of pure tungsten. The radioactive material is closely covered with a nonradioactive material. Then, glow discharge is caused between a starting auxiliary electrode and a main electrode closely adjacent to it, and then discharge is caused between the main electrodes to effect flashing. Heat generated by discharge of the flashing and impact of charged particles remove the cover donated to the auxiliary electrode, whereby radioactive materials appear in the discharged space. The radioactive materials can be sealed safely and securely in the tube. |
