|
|
|
| Monte-Carlo Simulation about Wall Correction Factor for the Spherical Graphite Cavity Chamber |
| HAO Yan-mei1,HUANG Jian-wei1,LI De-hong1,WANG Chen-yi1,2,WU Qi1,2 |
1.National Institute of Metrology, Beijing 100029, China
2.The University of South China, Hengyang, Hunan 421001, China |
|
|
|
|
Abstract Calculate the wall correction factor Kwall of spherical graphite cavity chambers by MC (Monte Carlo) method, and study the influence of Kwall about photon energy, wall thickness and graphite density. And the result shows that for the same volume chambers Kwall sharply reduces with energy at the low energy side. As the wall thickness increases, Kwall approximates linearly increase. And when the calculation accuracy is greater than 0.2%, the effect of density can be neglected on the simulation of Kwall. The above results indicate that in order to calculate the wall correction factor of the graphite cavity chamber accurartely, photon energy, wall thickness and graphite density must be considered.The above results indicate that the calculation of wall correction factor needs to consider the influence of photon energy,wall thickness and graphite density.And the calculation of correction factor of the graphite chamber ionization chamber must be high accuracy.
|
|
Received: 26 September 2017
Published: 19 April 2019
|
|
|
|
|
|
［1］李德红,王培玮,邬蒙蒙,等.137 Cs γ射线空气比释动能基准石墨空腔电离室的研制［J］.计量学报,2016,37(3).323-327.
Li D H, Wang P W, Wu M M, et al. Consstruction Graphite Cavity Ionization Chamber asAir Kerma Primary Standard for 137 Cs γ Rays［J］.Acta Metrologicala Sinica,2016,37(3).323-327.
［2］Nath R, Schulz R Z. Calculated response and wall correction factors for ionization chambers exposed to 60Co gamma rays.［J］.Medical Physics,1982,9(6):925-929.
［3］Bielajew A F. Ionisation cavity theory:a formal derivation of perturbation factors for thick-walled ion chambers in photon beams［J］. Physics in Medicine & Biology,2000,31(2):161-170.
［4］邬蒙蒙,李德红,王培伟,等.圆柱型空腔电离室修正系数的Monte Carlo模拟与实验验证［J］.计量学报,2016,37(2).214-218.
Wu M M, Li D H, Wang P W, et al. Monte Carlo Simulation and Experimental Validation of Correction Factor for Cylindrical Cavity Ionization Chamber［J］.Acta Metrologicala Sinica,2016,37(2).214-218.
［5］李德红,王培玮,成建波.137Cs γ射线空气比释动能率的国际关键比对［J］.原子能科学技术,2016,50(2):332-337.
LI De-hong, WANG Pei-wei, ChENG Jian-bo. International Key Comparison of Kerma Rate in 137Cs γ Ray［J］.Atomic Energy Science and Technology,2016,50(2):332-337.
［6］Attix F H. Introduction to radiological physics and radiation dosimetry［M］. John Wiley & Sons, 1986.
［7］Hubbell J H. Photon mass attenuation and mass energy-absorption coefficients for H,C,N,O,Ar,and seven mixtures from 0.1keV to 20MeV［J］.Radiation Research,1977,70(1):58-81.
［8］王坤,李涛,金孙均,等.圆饼电离室空气比释动能物理参量的蒙特卡洛模拟［J］.计量学报,2016,37(5).544-547.
Wang K, Li T, Jin S J, et al. Monte Carlo Simulation of Physical Parameters for Air Kerma Measurement by Graphite Pancake Ionization Chamber［J］.Acta Metrologicala Sinica, 2016,37(5).544-547.
［9］吴金杰,孙吉宁,杨元第,等.蒙特卡罗模拟计算中能X射线自由空气电离室电子损失修正因子［J］.计量学报,2010,31(6):555-557.
Wu J J, Sun J N, Yang Y D, et al. Correction Factor of Electron Loss for Medium-energy X-Ray Free-air Ionization Chamber Calculated with the Monte Carlo Method［J］. Acta Metrologicala Sinica,2010,31(6):555-557. |
|
|
|
2019, Vol. 40 
