Rehman Fazal-ur, Jamil K, Zakaullah M, Abu-Jarad F, Mujahid S A
Department of Physics, Quaid-e-Azam University, Islamabad, Pakistan.
J Environ Radioact. 2003;65(2):243-54. doi: 10.1016/s0265-931x(02)00100-5.
There are several methods of measuring radon concentrations but nuclear track detector cylindrical dosimeters are widely employed. In this investigation, the consequence of effective volumes of the dosimeters on the registration of alpha tracks in a CR-39 detector was studied. In a series of experiments an optimum radius for a CR-39-based open cylindrical radon dosimeter was found to be about 3 cm. Monte Carlo simulation techniques have been employed to verify the experimental results. In this context, a computer code Monte Carlo simulation dosimetry (MOCSID) was developed. Monte Carlo simulation experiments gave the optimum radius of the dosimeters as 3.0 cm. The experimental results are in good agreement with those obtained by Monte Carlo design calculations. In addition to this, plate-out effects of radon progeny were also studied. It was observed that the contribution of radon progeny (218Po and 214Po) plated-out on the wall of the dosimeters increases with an increase of dosimeter radii and then decrease to 0 at a radius of about 3 cm if a point detector has been installed at the center of the dosimeter base. In the code MOCSID different types of random number generators were employed. The results of this research are very useful for designing an optimum size of radon dosimeters.
测量氡浓度有多种方法，但核径迹探测器圆柱形剂量计被广泛应用。在本研究中，研究了剂量计有效体积对CR - 39探测器中α径迹记录的影响。在一系列实验中，发现基于CR - 39的开放式圆柱形氡剂量计的最佳半径约为3厘米。已采用蒙特卡罗模拟技术来验证实验结果。在此背景下，开发了一个计算机代码——蒙特卡罗模拟剂量学（MOCSID）。蒙特卡罗模拟实验得出剂量计的最佳半径为3.0厘米。实验结果与通过蒙特卡罗设计计算获得的结果吻合良好。除此之外，还研究了氡子体的沉积效应。观察到，如果在剂量计底部中心安装一个点探测器，沉积在剂量计壁上的氡子体（218Po和214Po）的贡献会随着剂量计半径的增加而增加，然后在半径约为3厘米时降至0。在MOCSID代码中使用了不同类型的随机数发生器。本研究结果对于设计最佳尺寸的氡剂量计非常有用。
