PRECISION25kVPULSEAND RFSUPPRESSIONINA 75kHzKICKER

rate of90kHzwithapulse widthof1gs[1]. The350V, 2A,supply provides theprimary current forall8stacks An international collaboration planstomeasure the ofthe4modulators: thesupply issettooperate at315V. lifetime (-2gs)ofthemuontoaprecision of1ppm.The Thespecifications forthekicker require therise and "MuLan"experiment isinprogress atthePaulScherrerfall timesofthedeflector plate voltage tobelessthan Institut (PSI) inSwitzerland. Thisexperiment requires a 45ns(10%to90%),andthetransient overshoot, atthe fast beamline kicker, whichcanturnthebeamonandoff,edgesofthepulse, tobeconsiderably less than10%.A toinvoke anartificial timestructure onthecontinuous typical operating moderequires adeflector voltage of0V beamwhichhasa50.6MHz timemicrostructure. The for5 s and25kV for22 s.During the5 s of0V kicker wasdesigned andbuilt atTRIUMFandinstalled at muonsareaccumulated inatarget. During the22gsof PSIinJune2003.Tests atPSIshowedthat RFfromthe pulse voltage, whenthemuonbeamnolonger hits the kicker interfered withexperimental detectors. Alsoitwas target, dataiscollected onthelifetime oftheaccumulated realized that thespecification fortheflattop ofthevoltagemuons. However themuonbeamisnot100%removed by pulse wasnotadequate forthisprecision experiment. thepulsevoltage andthosemuonsthatgetthrough Significant reduction intheRF andimprovement inthe contribute abackground tothemeasurement ofdecay pulse flattop wererequired. Thekicker wasreturned to time[2].Any systematic slopetothepulseflattop TRIUMF,andextensive changes weremade,basedon introduces atimedependence tothebackground [2]. detailed measurements andPSpice simulations. After the Themeasured RF emissions fromthekicker system changes theRF wasreduced byafactor ofmorethan aresynchronized withtherising andfalling edgesofthe 5000.Theflattop variation, fora22gspulse duration, HighVoltage (HV)pulses andoriginally rangformore wasreduced from0.18%toless than0.001%: inadditionthan1gs.Thisdominated thesignal inthedetector thepulse overshoot wasreduced from10%to2%. systembefore improvements weremadetothekicker system.