本文使用蒙特卡洛软件TOPAS (TOol for PArticle Simulation) 对质子束流经过发散型与传统型准直器限束孔后进入水模体中的过程建模，分析了两种准直器的边缘散射效应对剂量及中子能谱分布的影响，分别测试70,110, 160, 200,230,250MeV 能量下的质子束流，发现传统Aperture在70MeV的质子束下边缘散射效应最明显，在距水箱表面0.5cm 深度处横向剂量曲线平坦度、均匀度分别达到4.63%, 108.05%，随着深度增加边缘散射效应逐渐减弱，在布拉格峰位置处接近消失。使用发散型准直器限束孔后，在70MeV下平坦度、均匀度分别降至1.28%, 101.31%，对于100, 160, 200MeV 质子束均有不同程度改善。对于能量接近250MeV 的质子束，发散型准直器限束孔设置下横向剂量曲线并无优势。边缘散射效应导致的剂量不均随水深增加而减弱，对于各个能量质子，使用发散型准直器限束孔后次级中子减少。研究结果表明，发散型准直器限束孔应用于PSPT 效果显著，为进一步应用于临床提供数据支撑。
", "ds_source": "实验数据
", "ds_process_way": "利用蒙特卡洛软件TOPAS加工
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", "ds_acq_start_time": "2017-01-01 00:00:00", "ds_acq_end_time": "2019-12-31 00:00:00", "ds_acq_place": "甘肃兰州", "ds_acq_lon_east": null, "ds_acq_lat_south": null, "ds_acq_lon_west": null, "ds_acq_lat_north": null, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "apply-access", "ds_total_size": 6112174, "ds_files_count": 2, "ds_format": "pdf", "ds_space_res": null, "ds_time_res": "", "ds_coordinate": "无", "ds_projection": "", "ds_thumbnail": "934c80d7-fa32-4e1d-bd89-01a79b90203d.png", "ds_thumb_from": 0, "ds_ref_way": "", "paper_ref_way": "", "ds_ref_instruction": "", "ds_from_station": null, "organization_id": "9971252d-7beb-4464-bc08-bdcc5a1d7dd1", "ds_serv_man": "敏玉芳", "ds_serv_phone": "0931-4967596", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "", "subject_codes": [], "quality_level": 3, "publish_time": "2023-12-28 08:59:00", "last_updated": "2023-12-28 08:59:00", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.NCDC.IMP.DB4138.2023", "i18n": { "en": { "title": "Feasibility Study on Whether Divergent Aperture Can be Used on Proton Therapy Radiotherapy", "ds_format": "", "ds_source": "experimental data
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", "ds_ref_way": "", "ds_abstract": "In this paper, the process of proton beam passing through the beam limiting hole of divergent collimator and traditional collimator is modeled by using the Monte Carlo software Topas. The influence of the edge scattering effect of the two collimators on the dose and neutron spectrum distribution is analyzed. The proton beam at 70110, 160, 200, 230, 250 MeV energy is measured respectively, It is found that the edge scattering effect of traditional aperture is the most obvious under the proton beam of 70mev. The flatness and uniformity of the transverse dose curve at the depth of 0.5cm from the water tank surface reach 4.63% and 108.05% respectively. With the increase of depth, the edge scattering effect gradually weakens and disappears near the Bragg peak. The flatness and uniformity of the collimator are reduced to 1.28% and 101.31% respectively at 70mev after using the divergent collimator beam limiting hole. The 100, 160 and 200MeV proton beams are improved to some extent. For the proton beam with energy close to 250 MeV, the transverse dose curve of divergent collimator with beam limiting hole has no advantage. The dose difference caused by edge scattering effect decreases with the increase of water depth. For each energy proton, the secondary neutrons decrease after using the beam limiting hole of divergent collimator. The results show that the beam limiting hole of divergent collimator is effective in PSPT, which provides data support for further clinical application.
", "ds_time_res": "", "ds_acq_place": "Lanzhou, Gansu", "ds_space_res": "", "ds_projection": "", "ds_process_way": "Machining with Topas of Monte Carlo software
", "ds_ref_instruction": "" } }, "submit_center_id": "ncdc", "data_level": 0, "license_type": "CC BY 4.0", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "is_paper_in_submitting": false, "ds_topic_tags": [ "TOPAS", "准直器限束孔", "边缘散射" ], "ds_subject_tags": [], "ds_class_tags": [], "ds_locus_tags": [ "兰州", "甘肃省" ], "ds_time_tags": [ 2018 ], "ds_contributors": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "ds_meta_authors": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "ds_managers": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "category": "其他" }