Khan S, Alaamer A S, Tahir S N A
Pakistan Meteorological Department, Multan Airport, Pakistan.
Health Phys. 2008 Oct;95(4):433-5. doi: 10.1097/01.HP.0000318885.73725.fa.
7Be is a cosmogenic radionuclide with a half-life of 53.3 d produced mostly in the stratosphere by cosmic ray spallation of nitrogen and oxygen and entering the lower troposphere by atmospheric circulation processes. 7Be emits gamma rays of energy 477.6 keV and its concentration in the ambient air can be measured by gamma spectrometry. In the present study, the activity concentration of 7Be in outdoor ambient air of Lahore city, Pakistan, has been measured employing two air samplers and using a high purity germanium [HP(Ge)] detector. The 7Be activity concentration was found in the range from 1.6 to 11.3 mBq m(-3) with a mean value of 5.4 mBq m(-3).
7Be是一种宇宙成因放射性核素，半衰期为53.3天，主要在平流层由氮和氧的宇宙射线散裂产生，并通过大气环流过程进入对流层下部。7Be发射能量为477.6 keV的伽马射线，其在环境空气中的浓度可通过伽马能谱法测量。在本研究中，使用两个空气采样器并利用高纯锗[HP(Ge)]探测器测量了巴基斯坦拉合尔市室外环境空气中7Be的活度浓度。发现7Be活度浓度在1.6至11.3 mBq m(-3)范围内，平均值为5.4 mBq m(-3)。
