Power cables DC stress Luminescence Polymeric insulation Silver nanoparticles Polarity reversal Polymer Insulating polymers Space charge Charge trapping Charge transport Field distribution Current measurement Cross-linking by-products Electroluminescence Dielectric Polypropylene PTFE Electrical engineering Accumulation characteristics HVDC Polarization Electrodes Modeling Transport AFM Interfacial charge Cumyl alcohol Permittivity FTIR Fluid model Rotating machines Dielectric properties Electrical ageing Electron beams Cable Electrical conductivity Conductivity LDPE Charge d'espace Charge transport model DC conductivity Polymers Proteins Electric potential Dielectric charging SiO2 Electric field Electron beam Charge injection Cross-linked polyethylene Thin films Ac electric field HVDC cable Electrical properties Dielectric films LIMM Breakdown Thermal aging Radiation effects C-AFM Plasma processes Atomic force microscopy Epoxy resin FLIMM Pulsed electro acoustic method Silicon compounds Polyethylene Plasma process Electron-beam irradiation Dielectric materials Silver KPFM Nanostructured dielectrics Cathodoluminescence Electron emission Charge measurement Electromechanical stress Acoustic wave propagation Partial discharges AgNPs Dielectric material Electronic irradiation Optimization E-Beam PEA Electrical insulation Dielectrics Electric field distribution Mechanical properties Bipolar charge transport model EFM Aluminum oxide Dielectric strength Polyimide Ageing XLPE Insulation Conduction current Electrostatics