The ⁿMCP (Neutron sensitive microchannel plate) combined with advanced readout electronics is widely used in energy selective neutron imaging because of its good spatial and timing resolution. Neutron detection efficiency is a crucial parameter for the ⁿMCP. In this paper, a mathematical model based on the oblique cylindrical channel and elliptical pore was established to calculate the neutron absorption probability, the escape probability of charged particles and overall detection efficiency of ⁿMCP and analyze the effects of neutron incident position, pore diameter, wall thickness and bias angle. It was shown that when the doping concentration of the ⁿMCP was 10 mol%, the thickness of ⁿMCP was 0.6 mm, the detection efficiency could reach maximum value, about 24% for thermal neutrons if the pore diameter was 6 μm, the wall thickness was 2 μm and the bias angle was 3 or 6°. The calculated results are of great significance for evaluating the detection efficiency of the ⁿMCP. In a subsequent companion paper, the mathematical model would be extended to the case of the spatial resolution and detection efficiency optimization of the coating ⁿMCP.

所述^Ñ MCP（中子敏感的微通道板）配有先进的读出电子设备配合，可广泛使用在能量选择中子成像，因为它的良好的空间和时间分辨率的。中子探测效率是ⁿ MCP的关键参数。本文建立了基于斜圆柱通道和椭圆孔的数学模型，计算了ⁿ MCP的中子吸收概率、带电粒子逃逸概率和整体探测效率，分析了中子入射位置、孔径、壁厚和偏角。结果表明，当ⁿ MCP的掺杂浓度为 10 mol% 时，ⁿMCP为0.6 mm，当孔径为6 μm，壁厚为2 μm，偏角为3°或6°时，热中子的探测效率可以达到最大值，约为24%。计算结果对评估ⁿ MCP的检测效率具有重要意义。在随后的配套论文中，数学模型将扩展到涂层ⁿ MCP的空间分辨率和检测效率优化的情况。