Electrode design of coplanar-grid diamond film detectors by finite element method

The optimization of the electrode structure plays an important role in the improvement of the charge collection efficiency of diamond film radiation detector. In this paper the finite element (FE) method is utilized to design and optimize the electrode geometry. For 1×1 cm² diamond film model, the detector provided the best charge collection efficiency and energy resolution, when the ratio of the electric potential loaded on collecting grid and non-collecting grid was 0.9, collecting as well as non-collecting grids´ width were 25 μm and gaps´ width was 12.5 μm. Widening the second and last second grids to 50 μm could efficiently reduce the edge effect and the detector could have good uniformity.