GIS内X射线诱导带电粒子源项与放电敏感区关联模拟OA

X-ray-assisted partial discharge detection can provide initial electrons through radiation ionization,there-by reducing the statistical time lag of discharges at microscopic defects and enhancing excitation and detection prob-ability of concealed defects.In view of the ambiguity regarding radiation-induced secondary charge particle source terms under the multi-media coexistance condition of metals,gas and solid insulation within GIS,a full-scale GIS particle transport model incorporating SF6 gas,central conductor,metal enclosure,metal inserts,and epoxy insula-tors is developed using Geant4 in this study.Monte Carlo transport calculation is performed for incident photons and energies of 100 keV,1 MeV,5 MeV,and 10 MeV.By statically analyzing the statistical energy deposition,γ-photon interaction processes,generation channels of secondary electron and positron productio,as well as the spa-tial distribution of charged particles,the formation characteristics of the pre-ionization sources terms and their spa-tial correlation with potential discharge-sensitive regions are investigated.The results indicate that 100 keV photons are primarily shielded and constrained by the metal enclosure at the incident end,with secondary electrons exhibit-ing a short secondary range,and the pre-ionization sources terms being mainly concentrated near the enclosure and and metal inserts.At 1 MeV,Compton scattering accounts for 89.84%of the interactions,and the distribution of sec-ondary electrons extends toward the central conductor,insulator and the regions adjacent to gas gaps.Under the GIS geometric model and incident direction conditions adopted in this paper,5～10 MeV photons render the vinicity of the central conductor the primary region for energy deposition and interactions,where electron-positron pair produc-tion also occurs.The study results can provide source-term references for parameters selection in X-ray-assisted GIS defect detection and fo radiation-discharge coupled modeling.