SUBMICROSECOND RISETIME,200kVPEAK,MODULAR SOLIDSTATE TRIGGERUNITFOR ROTATINGARC GAP SWITCHOPERATION

II. PERFORMANCE REQUIREMENTS A self-contained Solid State Trigger Generator (subjectTheapproach forthetrigger generator, perCEA's ofthisarticle) hasbeensuccessfully implemented and requirements, excluded theuseofspark gapsandgas life-tested withitscompanion Rotating ArcGap(RAG) discharge tubes suchasthyratrons. Performance ofthe Coaxial Switch. Thisisinresponse toCEA'srequest fora trigger generator wasdictated bythespecification foran cost-effective, reliable, andmaintenance-free globalallsolid-state component approach andtherequirements switching solution fortheupcoming LMJ Facility in forsatisfactory operation oftheRAG switch. Thedesign, France. Thetrigger unit provides > 200kVpeaktrigger also, hadtobemodular toallowforeaseoftrigger pulse with < 350nsrisetime (1000 to90%)attheoutput of generator output pulse parameter optimization without a3m longRG-218cable. Theslewrateofthetrigger major re-design ofthehardware. Theflexibility toeasily pulserequired is-IkV/ns @100kVpeakamplitude. adjust output voltage anditsslewrate overawiderange These parameters, pre-determined viaRAG Switch trigger wasneeded tooptimize theRAG Switch operation. This tests, areadequate forprecise commandfiring theswitchneedruled outsingle point trigger circuit designs suchas operating atM = 4(pressure setsooperating voltage is those using asingle highvoltage pulse transformer anda 25%ofself-break voltage atthat pressure) value. With highvoltage solid-state switch assembly intheprimary 480eachofthese integrated switching systems required circuit. Table 1summarizes CEA'sspecifications. fortheLMJPowerConditioning Units (PCU), reliability ofthetriggering system isparamount tothesuccessful Table1.Trigger Generator Specifications. outcome ofthelaser fusion experiments. Theadopted Parameter CEARequirement design isanallsolid-state approach lending itself to Generator Type AllSolid State, Modular potential applications whereruggedness, precision, long