针对具有多丝、多条带结构特征的用于核物理实验的气体探测器, 采用节点组合法并利用有限元程序实现电场的计算。该方法构建宏观几何模型, 去除了丝状、条带状结构, 能够获得准确的计算结果。基于对该方法的验证, 以MSU研制的SπRIT-TPC为研究对象, 获得了该装置的二维电场分布以及电子在探测器中的漂移模拟结果。计算结果与GARFIELD程序得到的结果一致。采用节点组合法的有限元方法可用于复杂探测器结构的电场计算, 并用于后续的探测器模拟计算, 能够极大提高探测器的模拟效率。该方法也可适用于复杂结构的三维电场计算。

It is crucial to calculate the electric field distribution using Finite Element Analysis (FEA) program so as to do high efficiency simulation works for TPC gaseous detectors. A FEA program combined with the nodes positioning method has been employed to do the electric field calculation for TPC detectors, which basically have the geometry of multi-wire and multi-strip. After the tests of the nodes positioning method, we finished the electric field calculation and drift simulations for SπRIT-TPC, which had been constructed by MSU and other institutions. The calculation and simulation results agree well with those calculated by GARFIELD. Furthermore, 3D electric field calculation and the simulation for TPC detectors can also be done in a similar way.