Determination of effective atomic numbers from mass attenuation coefficients of tissue-equivalent materials in the energy range 60 keV-1.33 MeV

10th International Seminar on Medical Physics; 1st AMDI International Oncology Symposium

物理学;医药卫生

Amin, Noorfatin Aida B.^1 ; Zukhi, J.^1 ; Kabir, N.A.^2 ; Zainon, R.^1

Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Pulau Pinang

13200, Malaysia^1

School of Physics, Universiti Sains Malaysia, Pulau Pinang

11800, Malaysia^2

关键词: Attenuation coefficient;    Effective atomic number;    Effective electron densities;    Mass attenuation coefficients;    Photomultiplier tube;    Radioactive sources;    Theoretical values;    Tissue-equivalent materials;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/851/1/012018/pdf
DOI  :  10.1088/1742-6596/851/1/012018

学科分类：卫生学

来源: IOP

【 摘 要 】

The main aim of this study was to establish a cost-effective tissue-equivalent material for phantom fabrication. Effective atomic numbers (Zeff) and effective electron densities (Neff) were calculated based on mass attenuation coefficient values. The linear and mass attenuation coefficients of two samples of paraffin wax and NaCl compositions were measured using Si detector for NaI (Tl) detector of 1.5" resources. Radioactive source was placed in front of detector and the sample was placed between the source and the photomultiplier tube (PMT) of the detector. The real time was set for 6000 seconds. The photopeak, full width at half maximum (FWHM) and net area of photopeak were measured using Meastro software. The attenuation coefficient values obtained from this study were used to calculate Zeffand Neffof paraffin wax and NaCl compositions. The measured results were compared with the theoretical values from XCOM and ICRU Report 44. The relative percentage difference of mass attenuation coefficients between experimental and human tissue for both paraffin wax and NaCl mixture are below 5%, whereas the relative percentage difference of Zeffand Neffare above 5%.The measured values of Zeffand Neffof paraffin wax and NaCl help us to establish the optimal mixtures to fabricate a cost-effective tissue-equivalent material.