本底计数

采用铅屏蔽、激光脉冲和线性门同步符合技术将HPGeX射线谱仪的本底计数率降低到10-4炮，满足了单光子计数时的低本底要求。

By use of Pb shielding and coincidence technology , the background counts are kept below 10 - 4 per shot , which satisfies the low background requirement of single photon incident .

在铅屏蔽室内，γ光子能量从0.05&2MeV范围本底计数率为1053计数/min。

The background counts of r-ray photons , whose energy range is from 0.05 to 2 MeV , is 1053 cpm in the lead shield .

在线~（14）C年龄测定系统不但能测量~（14）C计数，而且能测出~（14）C能谱和有较低的本底计数率。

The radioactivity of ( 14 ) ~ C and its β spectrum can be measured in low count-rate background .

在100～2000keV能区，相对效率为38.4%的HPGe探测器积分本底计数率为0.7／s，本底效率比为1.82／s；

In this system , the background counting rate is 0.7/s and background efficiency ratio is 1.82/s for HPGe detector of 38.4 % relative efficiency in 100 ~ 2 000 keV energy range .

研究了一种容积为75ml的高灵敏的闪烁室，其探测效率～82%，本底计数率～0.09计数/min。

A high-sensitive scintillation chamber of 75 ml in volume with detection efficiency ~ 82 % and background counting rate ~ 0.09 cpm has been developed .

临界实验中本底计数对倒数外推临界质量的影响

Effect of Background Counting on Reciprocal Extrapolation in Criticality Experiment

探测器的本底计数率为4―6脉冲1分。

The background count of the detector is 4 ~ 6 counts 1 min.

着重论述了本底计数对倒数外推方法的影响。

The paper particularly introduces the effect of background counting on the reciprocal extrapolation method .

用该方法在实验室试验结果表明，可较好地克服本底计数波动的干扰.提高测钾精度。

Experimental data showed that such a technique could reduce the adverse effect caused by the random fluctuating of base count , and therefore improve the procession of potassium determination .

低本底脉冲计数装置

Low background pulse counting assembly

放射性监控仪器一般是根据辐射场强度变化量的大小给出报警信号，通常将探测器当前计数与本底平均计数进行比较，当两者的差值超过一定的范围，就给出警示信号。

Radiation monitoring equipment give alarm signal according to the radiation intensity ; monitoring the current count and the background average count , and gives a warning signal when the difference between the two over a certain range .

低本底液体闪烁计数法测量环境样品中~（90）Sr

Direct Determination ot 90 ~ Sr in Environmental Samples by Ultra Low-Level Liquid Scintillation Counting

实验表明，计数器固有本底为0.002计数/（min·Cm~2）（2计数/min）。

It has been shown that the intrinsic radioactive background of the apparatus is 0 . 002 cpm / cm2 ( 2 count / min ) .

利用不同标定源对美国Daybreak582、583型低本底厚源ZnSA1pha计数仪光电倍增管高压（HV）和积分甄别器阈值电压（DISC）进行了标定，并与示波器标定结果进行了对比。

First , this study compares thick source ZnS alpha-counting calibration results of the photomultiplier tube ( PMT ) high voltages and thresholds calibrated by the oscillograph with those by different sources .

在规定的时间内，测量样品放射性的时间和测量本底的时间之比等于放射性总计数和本底计数率之比的平方根时，测量结果的误差为最小。

Within the fixed time , when a ratio of measured time for radioactive sample to background equals the ratio of square root of radioactive count for radioactive sample to background , there are minimal measure errors .