采样和计数技术的新进展提供了测量天然水中低活度的~(226)Ra、~(228)Ra 和~(224)Ra 的方法。样品在现场浓集,将镭吸附在涂有锰氧化物的纤维上。绝对活度和活度比用锗探测器测量,在某些情况下,用α闪烁法测量~(222)Rn 作为补充。本文叙述采用一个Ge(Li)晶体和一个有1 cm 直径、4 cm 深井孔的本征锗晶休进行的实验及其结果。同时列出了检验水样、实际地面水和河口水的结果,以证实用锗探测器作天然水中镭的研究之适用性。 New Developments in Sampling and Counting Techniques The methods for measuring low activity 226 (Ra), (228) Ra and ~ (224) Ra in natural waters are provided. Concentrate the sample in the field, the adsorption of radium in the manganese oxide coated fibers. The absolute activity and activity were measured using a germanium detector. In some cases, ~ (222) Rn was measured by alpha scintillation as a supplement. This paper describes the experiments and results of an intrinsic Ge crystal using a Ge (Li) crystal and a 1 cm diameter, 4 cm deep well. The results of testing water samples, actual surface water and estuarine water are also listed to demonstrate the applicability of germanium detectors for radium in natural waters.