Effect of the geometrical parameters on the electric field of pixelated two-dimensional arrays of γ-ray spectrometers

We study the effect of the geometrical parameters of pixelated two-dimensional (2D) arrays of γ-ray spectrometers upon the distribution of the electric field lines, which are induced by the applied voltage. It is shown that the size and in particular the separation between anodes strongly affect the field uniformity. The electric field is calculated by three methods including: (i) a commercial software for 3D field analysis based on finite element method; (ii) a 3D finite difference approach; and (iii) the Moments method. The required boundary conditions and the calculation efficiency of each method are compared. Since the uniformity of the electric field strongly affects the spectral performance of pixelated 2D arrays of γ-ray spectrometers, the results presented here are important for the optimal design and modeling of such arrays.