Abstract: Presently， structureoptimizationandtechnologicaltreatmentaretwomainwaystodepressthestrongelectromagn eticfieldbreakdown.Theenergydepositionabout1MeVelectronsinmetalmaterialswasinvestigatedby BetheenergylosslawandMonteCarlosimulation.Theresultsindicatethattheelectronsinthe materialofsmalleratomicnumberanddensityhavemuchlongereffectiverangeandlowerenergydepo sitiondensity.Thereby， thematerialismoreresistanttoelectronsbombardmentandthebreakdownriskcanbeeffectivelyre duced.Withthesameincidentelectronenergy，thecopper， stainlesssteelandtitaniumwereexperimentallycompared.Owingtoitshighdensity， thecopperisdestroyedmosteasily.Simultaneously，thetitaniumshowsgoodperformanceforitslow density.Thefurtherhighpowermicrowave（HPM）experimentsshowthat，with~2.8GWoutput， theoutputmicrowavepulsewidthoftheRBWOcanbeincreasedto27nsfrom18nswhenthestain lesssteelissubstitutedbythetitaniumandthepulseshorteningiseffectivelydepressed.

Key words: breakdown, energydeposition, effectiverange, MonteCarlo, electronsbombardment, materials, relativisticbackwardwaveoscillator