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The monocrystalline silicon neutron beam window is one of the key components of neutron spectrometers and thin circular plate.Monocrystalline silicon is a brittle material and its strength is not constant but is consistent with the Weibull distribution. The window is designed not simply through the average strength, but according to the survival rate. Bending deformation is the main form of the window, so dangerous parts of the neutron beam window is stress-linearized to the combination of membrane stress and bending stress. According to the Weibull distribution of bending strength of monocrystalline silicon based on a large number of experimental data, finally the optimized neutron beam window is 1.5mm thick. Its survival rate is 0.9994 and its transmittance is 0.98447; it meets both physical requirements and the mechanical strength., Comment: 5 pages, 8 figures

NASA’s Artemis program will return astronauts to the lunar surface using a Human Landing System staged at Gateway’s 9:2 L2 southern NRHO. The current study explores global lunar access for Gateway’s baseline NRHO and a comparable butterfly orbit. Additionally, increasing transfer time and loitering in low lunar orbit are analyzed to reduce lunar surface access costs. The results show selecting the optimal staging orbit for a landing site, increasing transfer times, and leveraging low lunar orbit loiter greatly reduce performance requirements.