三维辐射场是反映核设施内真实外照射分布的重要数据库，可为核设施现场建立有效的屏蔽措施及确定合理的作业方案提供数据基础。为了重构出与实际较为相符的三维γ辐射场，结合点核积分理论，该文利用最小二乘法和Gauss-Seidel迭代算法，建立了基于源活度反演计算的γ辐射场重构方法，研究了所选取测量点位置对源活度反演结果的影响，并结合某核电现场的实地测量数据对该重建方法进行了实验验证与计算分析。结果表明：在现场实验中基于源活度反演算法重构出的γ辐射场数据与相对应的测量数据之间的偏差约为10%，能够满足核设施现场辐射防护的计算需要，可为其现场的辐射防护最优化提供技术支持。
Three-dimensional radiation fields must be known to predict the distribution of real external exposures in nuclear facilities. Such data fields provide the basis for establishing effective shielding measures and determining reasonable operating plans at nuclear facilities. Three-dimensional gamma radiation fields were reconstructed using point-kernel integral theory and a source activity inversion algorithm using the least squares method and a Gauss-Seidel iterative algorithm. The results were then used to study the influences of the dose measurement positions on the source inversion results. The reconstruction method was verified using measured data from a nuclear power plant. The results show about 10% difference between the reconstructed gamma radiation field data and the measured data which is sufficient for radiation protection studies of nuclear facilities and for optimizing radiation protection procedures.
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