چاپ صفحه |  صفحه نخست سامانه |  چکیده مقاله |  نویسندگان |  دانلود مقاله | دانشگاه علوم پزشکی تبریز |
| Aim: The aim of this study was to characterize the radiation contamination inside and outside the megavoltage radiotherapy room. Background: Radiation contamination components in the 18 MV linac room are the secondary neutron, prompt gamma ray, electron and linac leakage radiation. Materials and Methods: An 18 MV linac modeled in a typical bunker employing the MCNPX code of Monte Carlo. For fast calculation, phase-space distribution (PSD) file modeling was applied and the calculations were conducted for the radiation contamination components dose and spectra at 6 locations inside and outside the bunker. Results: The results showed that the difference of measured and calculated percent depth-dose (PDD) and photo beam-profile (PBP) datasets were lower than acceptable values. At isocenter, the obtained photon dose and neutron fluence were 2.4 × 10−14 Gy/initial e◦ and 2.22 × 10-8 n◦/cm2, respectively. Then, neutron apparent source strength (QN) value was found as 1.34 × 1012 n◦/Gy X at isocenter and the model verified to photon and neutron calculations. A surface at 2 cm below the flattening filter was modeled as phase-space (PS) file for PDD and PBP calculations. Then by use of a spherical cell in the center of the linac target as a PS surface, contaminant radiations dose, fluence and spectra were estimated at 6 locations in a considerably short time, using the registered history of all particles and photons in the 13GB PSD file as primary source in the second step. Conclusion: Designing the PSD file in MC modeling helps user to solve the problems with complex geometry and physics precisely in a shorter run-time. |
| نویسنده | نفر چندم مقاله |
|---|---|
| امیر قاسمی جنگجو | اول |
| نام فایل | تاریخ درج فایل | اندازه فایل | دانلود |
|---|---|---|---|
| 1-s2.0-S1507136720300110-main (5).pdf | 1399/01/26 | 1748735 | دانلود |
