Wälzlein C, Scifoni E, Krämer M, Durante M
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, D-64291 Darmstadt, Germany. Frankfurt Institute for Advanced Studies FIAS, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany. Technische Universität Darmstadt, Darmstadt, Germany.
Phys Med Biol. 2014 Mar 21;59(6):1441-58. doi: 10.1088/0031-9155/59/6/1441. Epub 2014 Feb 28.
A possible dose enhancement effect by proton or electron irradiation in the vicinity of nanoparticles consisting of different high Z atomic materials has been investigated using the track structure Monte Carlo code TRAX. In the simulations, Fe, Ag, Gd, Pt and Au nanoparticles (r = 22 and 2 nm) were irradiated with monoenergetic proton beams at energies of therapeutic interest (2, 80 and 300 MeV) and 44 keV electrons. Due to the large number of electrons in atoms with high atomic numbers, many electrons can be released in Auger cascades in addition to the primary ionization process. The potential additional nanoscopic radial dose contributions in the presence of metallic nanoparticles are assessed by comparison with liquid water and water simulated with the same density as the metallic materials. We find a noticeable impact of Auger electrons emitted from the nanoparticles. Special focus has been given to the assessment of complete sets of low-energy electron cross sections for the nanoparticle materials.
使用径迹结构蒙特卡罗代码TRAX，研究了在由不同高Z原子材料组成的纳米颗粒附近，质子或电子辐照可能产生的剂量增强效应。在模拟中，用具有治疗意义的能量（2、80和300 MeV）的单能质子束和44 keV电子辐照Fe、Ag、Gd、Pt和Au纳米颗粒（半径分别为22和2 nm）。由于高原子序数原子中有大量电子，除了初级电离过程外，许多电子还能在俄歇级联反应中释放出来。通过与液态水以及模拟的与金属材料密度相同的水进行比较，评估了金属纳米颗粒存在时潜在的额外纳米级径向剂量贡献。我们发现纳米颗粒发射的俄歇电子有显著影响。特别关注了纳米颗粒材料低能电子截面完整数据集的评估。
