基于对氦离子照射后扩大抗辐射细胞实验数据库的极大兴趣，HTB140、MCF-7和HTB177人类恶性细胞被暴露于具有不同线性能量转移（LET）的氦离子束。细胞沿加宽的 62 MeV/u 氦离子布拉格峰，提供 4.9、9.8、23.4 和 36.8 keV/μm 的 LET。实验设计采用 Geant4 工具包进行数值模拟。评估细胞存活率并与参考 γ 射线进行比较。 DNA双链断裂通过γ-H2AX焦点进行评估。随着LET的增加，2 Gy下的存活分数减少，而RBE（2 Gy，γ）逐渐增加。对于HTB140细胞，高于4Gy的剂量，观察到存活轻微饱和，而RBE（2Gy，γ）的增加不受影响。随着 LET 的增加，γ-H2AX 焦点的增加在照射后 0.5 小时显现出来。相同 LET 的细胞系之间的焦点数量没有显着差异。从0.5到24小时，病灶数量下降达到其残留水平。对于每个时间点，三种细胞系之间的 DNA DSB 存在微小差异。对经氦离子照射的三种细胞系（具有不同的 LET）获得的数据进行分析，揭示了高消除能力和产生大量 DNA DSB 的能力。相对于 γ 射线，介于质子和碳离子报道的之间。

Based on considerable interest to enlarge the experimental database of radioresistant cells after their irradiation with helium ions, HTB140, MCF-7 and HTB177 human malignant cells are exposed to helium ion beams having different linear energy transfer (LET).The cells are irradiated along the widened 62 MeV/u helium ion Bragg peak, providing LET of 4.9, 9.8, 23.4 and 36.8 keV/µm. Numerical simulations with the Geant4 toolkit are used for the experimental design. Cell survival is evaluated and compared with reference γ-rays. DNA double strand breaks are assessed via γ-H2AX foci.With the increase of LET, surviving fractions at 2 Gy decrease, while RBE (2 Gy, γ) gradually increase. For HTB140 cells, above the dose of 4 Gy, a slight saturation of survival is observed while the increase of RBE (2 Gy, γ) remains unaffected. With the increase of LET the increase of γ-H2AX foci is revealed at 0.5 h after irradiation. There is no significant difference in the number of foci between the cell lines for the same LET. From 0.5 to 24 h, the number of foci drops reaching its residual level. For each time point, there are small differences in DNA DSB among the three cell lines.Analyses of data acquired for the three cell lines irradiated by helium ions, having different LET, reveal high elimination capacity and creation of a large number of DNA DSB with respect to γ-rays, and are between those reported for protons and carbon ions.