电子FLASH-RT剂量学模拟计算与实验研究

程德琪; 羊奕伟; 王诗岚; 唐镭迅; 王翔

doi:10.11884/HPLPB202436.240096

电子FLASH-RT剂量学模拟计算与实验研究

doi: 10.11884/HPLPB202436.240096

1.
哈尔滨工程大学核科学与技术学院，哈尔滨 150001
2.
中国工程物理研究院应用电子学研究所，四川绵阳 621900
3.
南华大学核科学技术学院，湖南衡阳 421001

基金项目: 国家自然科学基金项目(12375318)

详细信息

作者简介:
程德琪，chengdeqi@hrbeu.edu.cn

通讯作者:
王　翔，xiang.wang@hrbeu.edu.cn。

中图分类号: R144.1
计量
- 文章访问数: 83
- HTML全文浏览量: 41
- PDF下载量: 9
- 被引次数: 0
出版历程
- 收稿日期: 2024-03-14
- 修回日期: 2024-09-09
- 录用日期: 2024-09-09
- 网络出版日期: 2024-09-13
- 刊出日期: 2024-10-15

Electron FLASH-RT dosimetry simulation and experimental research

1.
College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China
2.
Institute of Applied Electronics, CAEP, Mianyang 621900, China
3.
School of Nuclear Science and Technology, University of South China, Hengyang 421001, China

摘要

摘要: 通过实验测量与数值模拟相结合的方法评估电子FLASH-RT的剂量学特性。实验中，使用EBT3胶片在固体水模中测量剂量，同时采用MCNP5程序模拟验证束流特征参数。实验平台基于9 MeV电子直线加速器构建，通过调整加速器参数，在源皮距1 m处实现了250 Gy/s的超高剂量率。实验与模拟结果在剂量分布上的最大偏差不超过5%，束流平坦度控制在3%以内。关键剂量率评估显示，加速器在最大工况下工作，可获得满足FLASH效应所需的超高剂量率。离轴剂量变化研究表明，引出窗中水层的存在改善了束流的均匀性。中心轴深度剂量分布分析表明，模拟与实验结果在水层厚度10 mm时吻合较好。二维剂量分布显示，模拟结果与EBT3胶片测量趋势一致。研究结果表明，电子FLASH-RT实验平台能够提供所需的超高剂量率，且实验与模拟结果具有较高的一致性，为FLASH-RT的进一步研究和应用提供了重要的剂量学参数和束流特征参考。
- 超高剂量率 /
- 电子FLASH-RT /
- 蒙特卡罗模拟 /
- 剂量分布 /
- 束流特征参数
Abstract: This study aims to evaluate the dosimetric characteristics of electron FLASH-RT by combining experimental measurements with numerical simulations. In the experiment, EBT3 films were used to measure doses in solid water phantoms, while the MCNP5 program was employed to simulate and verify beam characteristics. The experimental platform was constructed based on a 9 MeV electron linear accelerator, and by adjusting the accelerator parameters, an ultra-high dose rate of 250 Gy/s was achieved at a source-to-surface distance of 1 m. The maximum deviation between experimental and simulated results in dose distribution did not exceed 5%, and the beam flatness was controlled within 3%. Key dose rate assessments show that the accelerator can work at maximum conditions to achieve the ultra-high dose rate required for the FLASH effect. Off-axis dose variation studies indicate that the presence of a water layer in the extraction window improved the uniformity of the beam. Central axis depth dose distribution analysis showes that the simulation and experimental results matched well at a water layer thickness of 10 mm. The two-dimensional dose distribution showes that the simulation results are consistent with the EBT3 film measurements. The study results demonstrate that the electron FLASH-RT experimental platform can provide the required ultra-high dose rate, and there is a high degree of consistency between experimental and simulation results, providing important dosimetric parameters and beam characteristic references for further research and application of FLASH-RT.
- ultra-high dose rate /
- electron FLASH-RT /
- Monte Carlo simulation /
- dose distribution /
- beam characteristic parameters

HTML全文

图 1 电子FLASH-RT实验平台示意图

Figure 1. Schematic diagram of electron FLASH-RT experimental platform

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图 2 胶片平行于束流放置

Figure 2. Film is placed parallel to the beam direction

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图 3 MC模型示意图

Figure 3. Monte Carlo simulation diagram

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图 4 五次独立重复实验下不同深度处剂量的相对偏差

Figure 4. Relative deviation of the dose at different depths under five independent repeated experiments

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图 5 引出窗不同水层厚度下的离轴比曲线

Figure 5. Off-axis ratio curves at different water-layer thicknesses

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图 6 EBT3胶片和MC剂量分布曲线

Figure 6. EBT3 film and MC dose distribution curve

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图 7 EBT3胶片离轴比剂量分布曲线

Figure 7. Off-axis ratio dose distribution curve of EBT3 film

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图 8 水层厚度对百分深度剂量影响

Figure 8. Effect of water-layer thickness on the Percentage Depth Dose (PDD)

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图 9 EBT3胶片和MC模拟的深度剂量分布曲线

Figure 9. Depth dose distribution curves of EBT3 film and MC simulation

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图 10 EBT3胶片和MC模拟的二维剂量分布

Figure 10. Two-dimensional dose distribution of EBT3 film and MC simulation

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图 11 不同能量电子束的百分深度剂量曲线

Figure 11. PDD curves for electron beams at different energies

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图 12 电子束百分深度剂量随照射野大小的变化

Figure 12. PDD of the electron beam varies with field sizes

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图 13 射野中心轴横向电子分布

Figure 13. Lateral electron distribution in central-axis field size

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图 14 不同射野下的离轴比曲线

Figure 14. Off-axis ratio curves under different field sizes

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