Saito T, Watanabe K, Morikawa N
Radioisotopes. 1979 Oct 15;28(10):603-8. doi: 10.3769/radioisotopes.28.10_603.
A long path internal gas flow proportional counter was devised was to be used as a high sensitivity detector for radio gas chromatography, and its performance characteristics were investigated. The long path counter tube used for this detector has a sufficiently long passage in comparison with the diameter. The counter tube for general use is made of brass or copper tube 1 cm in diameter, 100 cm in length with a mirror finish on all internal surface, and the center electrode is of tungsten wire 0.05 mm in diameter. For actual use, several of these counter tubes are connected in series in assembly to hold the total volume of a gas sample in the counting system over a desired counting period. Thus this flow detector as an integral type one and gives directly a counting rate. Experiments showed that the dynamic counting efficiencies of tritium and carbon-14 were about 90% and equal to the static counting efficiencies. Furthermore, with this detector, the counting rate does not appear to be affected by minor variations of the effective inner volume of the counter tube and the flow rate of counting gas.
设计了一种长路径内气体流动比例计数器，用作放射性气相色谱的高灵敏度探测器，并研究了其性能特征。用于该探测器的长路径计数管与直径相比有足够长的通道。一般使用的计数管由直径1厘米、长度100厘米的黄铜管或铜管制成，其内表面全部抛光，中心电极是直径0.05毫米的钨丝。实际使用时，将几个这样的计数管串联组装，以便在所需计数周期内使计数系统中气体样品的总体积保持不变。因此，这种流动探测器是一体式的，可直接给出计数率。实验表明，氚和碳-14的动态计数效率约为90%，与静态计数效率相当。此外，使用该探测器时，计数率似乎不受计数管有效内部体积和计数气体流速微小变化的影响。
