1.1本试验方法包括通过测定裂变产物的量来测量反应速率 99 非阈值反应产生的钼 241 Am（n，f）， 235 U（n，f），和 239 Pu（n，f）和阈值反应 238 U（n，f）， 237 Np（n，f），和 232 Th（n，f）。 1.2这些反应产生许多裂变产物，其中包括 99 钼的半衰期为65.94小时。由于在完成伽马射线能谱测定时未分辨或干扰伽马射线，其他裂变产物的竞争活动需要采用化学分离来分离 99 瞬间。 99 钼发射几种能量的伽马射线，很容易被伽马射线探测和识别- 射线光谱仪。 1.3使用合适的技术，可以在10范围内测量中子注量率 到大约10 14 n[点]厘米 [点]s . 1.4用裂变剂量计测量时间积分反应速率 99 Mo分析受到 钼的辐照时间可达300小时左右。 1.5以国际单位制表示的数值应视为标准。 1.6本标准无意解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。

1.1 This test method covers the measurement of reaction rates by determining the amount of the fission product 99 Mo produced by the non-threshold reactions 241 Am(n,f), 235 U(n,f), and 239 Pu(n,f) and by the threshold reactions 238 U(n,f), 237 Np(n,f), and 232 Th(n,f). 1.2 These reactions produce many fission products, among which is 99 Mo, having a half-life of 65.94 h. Because of unresolved or interfering gamma rays when gamma-ray spectrometry is accomplished, the competing activity from other fission products requires that a chemical separation be employed to isolate the 99 Mo. 99 Mo emits gamma rays of several energies, which are easily detected and identified by a gamma-ray spectrometer. 1.3 With suitable techniques, neutron fluence rates can be measured in the range 10 to approximately 10 14 n[dot]cm [dot]s . 1.4 The measurement of time-integrated reaction rates with fission dosimeters by 99 Mo analysis is limited by the half-life of Mo to irradiation times up to about 300 h. 1.5 The values stated in SI units are to be regarded as the standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.