| 摘要 |
<p>A scintillator cell, particularly for detecting tritiated water in a flowing gas stream, consists of a double spiral of scintillator sheets 20, 21 defining a thin gas flow path, and side windows (16, 17) (Fig. 1, not shown) preferably also of the scintillator material, optically coupled to the edges of the spiral. The sheets, e.g. 0.005 inch thick, 1 mm. apart, provide surfaces upon which the water vapour condenses giving a thin moisture film (40) (Fig. 3, not shown) during the gas flow, and the sheets act as light guides, leading the produced scintillations to the cell windows. The cell may be mounted in a metal case, and be lightly lead shielded. The gas may be pumped through the cell from inlet port 13 to outlet port 14, and photomultiplier tubes may be mounted adjacent each window. The assembly of the cell, using polyethylene and string spacers, is described. A standard coincidence counting circuit is described (Fig. 4, not shown).</p> |
