| 摘要 |
PURPOSE:To encapsulate a radioactive material in a light emitting tube safely and reliably, by holding a radioactive material having short half-life on an electrode then coating said holding section with nonradioactive material and encapsulating in a tube and removing said coating by such as electronic shock. CONSTITUTION:Radioactive material such as <22>Na, <54>Mn, <60>Co having half-life longer than 0.5 year and shorter than 10 years while the radioactive capacity per single light emitting tube is less than 1mu Curie is coated previously on aux. electrode composed of pure tungsten, then said radioactive material is coated tightly with nonradioactive material, preferably the light emitting metal to be encapsulated in the tube or its oxide which isn't remained as an impurity in the tube. After encapsulating such aux. electrode in the light emitting tube, said coating is removed by the heat associated with the discharge or the electronic shock to encapsulate the radioactive material in the tube. Consequently a radioactive material having short half-life can be encapsulated in a light emitting tube safely and reliably. |
