| 摘要 |
<PICT:1011235/C4-C5/1> A self-luminous light source comprises a container 1, e.g. of glass or polymethyl methacrylate, containing a radio-nuclide, e.g. tritium, krypton 8, 5, or a solid radio-nuclide, and having phosphor 7 coated surfaces within the envelope and a reflective layer 8 over part of the outside of the envelope. The spacing between the internal surfaces 4 may be equal to the mean free path of a b -particle in the gas 9 in the source, and the thickness of the layer of phosphor 7 may be equal to the range, in the phosphor, of the particles emitted by the radio-nuclide. |
