文档介绍：,s。.,2007======================================================一BestC4+andC5+)(NationalIn8tituteofRadiologicalsciences,chiba263—8555,J印an)AbstractWiththeprototypeECRionsourceforthenextcarbonther印yfacilityinJ印aJlanewseriesofmeaLsurementshaLsbeenperformedinorder(a)tofindthehi曲estbeamcurrentsofc4+ions,and(b)tostudytheef五ectof“special”gas—mi)(poundasafeedAnisotopice妇奄cthasbeenfoundinapreViousexperiment:withdeuteratedmethane(CD4gas)thec5+beamcurrentsareabout10%higherthanwithregul盯methane(cH4gas).Forbutanegases(c4D10andc4H10respectively)tbeisotopice&ctforc6+productionevenstronger(>15%).Forproductionofc4+ionstheisotopice&ctappearstobeabsent-Itturn8outthattherelativeamountofc盯bonmuchmoreimportaJlt:acetylenegives15%higherC叶currentthanbutane,whichinturngive8about10%higherC4+,ECRionsource,i80topice船ct,gas—mixing1IntroductionAnewcarbontherapyfacility,presentlybeingconstructedatNIRS,needsanionsourcetoproducecarbonionsinchargestate4+—cifictheionsshouldhaveanenergyof10keV/uwithaminiⅡmmintensityof50particle¨—ECRIS(calledKeisource)wasshownll’thataC4+beamof200euAatextrac—【刈ofthissource,calledKei2,