^(252)Cf裂变中子源在组织等效模体中的中子和γ辐射剂量分布的计算

Calculation of dose distribution for^(252)Cf fission neutron source in tissue equivalent phantoms using Monte Carlo method

目的 计算2 5 2 Cf裂变中子源的中子和γ辐射在组织等效模体内的剂量分布 ,为使用2 5 2 Cf裂变中子源进行中子放疗提供有用的剂量学参数。方法 建立2 5 2 Cf源和组织等效模体的三维几何计算模型 ,利用蒙特卡罗方法进行中子和γ辐射联合输运计算。结果 计算了两种医用2 5 2 Cf裂变中子源在水、血液、肌肉、皮肤、骨骼和肺组织等效材料构成的模体中距源不同距离点处的中子和γ辐射吸收剂量。结论 蒙特卡罗计算结果与文献数据以及使用双电离室实验测量的结果符合得较好。对2 5 2 Cf裂变中子源在 5种组织材料构成的模体中中子和γ辐射的剂量分布进行了比较 ,使用水作为组织等效材料对2 5 2 Cf裂变中子源在以肌肉、血液和皮肤构成的局部组织内的剂量分布进行模拟计算 ,可取得比较可靠的结果。

Objective\ To provide useful parameters for neutron radiotherapy,this paper presents results of a Monte Carlo simulation study investigating the dosimetric characteristics of linear 252 Cf fission neutron sources. Methods\ A 252 Cf fission source and tissue equivalents phantom were modeled.The dose of neutron and gamma radiations were calculated using Monte Carlo Code. Results\ The dose of neutron and gamma at several positions for 252 Cf in the phantom made of equivalent materials to water,blood,muscle,skin,bone and lung were calculated. Conclusion\ The results by Monte Carlo methods were compared with the data by measurements and references.According to the calculation,the method using water phantom to simulate local tissues such as muscle,blood and skin is reasonable for the calculation and measurements of dose distribution for 252 Cf.\;