Michael Neubauer

High Power Coax Window

A suxadperxadconxadductxading RF (SRF) power couxadpler caxadpaxadble of hanxaddling 500 kW CW RF power is rexadquired for prexadsent and fuxadture storxadage rings and linacs. There are over 35 couxadpler dexadsigns for SRF cavxadixadties rangxading in frexadquenxadcy from 325 to 1500 MHz. Couxadpler winxaddows vary from cylinxadders to cones to disks, and RF power couxadplers are limxaditxaded by the abilxadixadty of cexadramxadic winxaddows to withxadstand the stressxades due to heatxading and mexadchanxadixadcal flexxadure. We proxadpose a novel roxadbust co-axxadixadal SRF couxadpler dexadsign which uses comxadpressed winxaddow techxadnolxadoxadgy. This techxadnolxadoxadgy will allow the use of highxadly therxadmalxadly conxadducxadtive maxadtexadrixadals for cryoxadgenic winxaddows. Using comxadpressed winxaddow techxadniques on disk co-axxadixadal winxaddows will make sigxadnifxadixadcant imxadprovexadments in the power hanxaddling of SRF couxadplers. We prexadsent the bench test rexadsults of two winxaddow asxadsemxadblies back to back, as well as inxaddixadvidxaduxadal winxaddow VSWR in EIA3.125 coax. A vacxaduxadum test asxadsemxadbly was made and the winxaddows baked out at 155C. The proxadcessxades used to build winxaddows is scalxadable to largxader dixadamxadexadter coax and to highxader power levxadels.

IMPROVED DC GUN INSULATOR ASSEMBLY

Many user faxadcilxadixadties such as synxadchrotron raxaddixadaxadtion light sources and free elecxadtron lasers rexadquire acxadcelxaderxadatxading strucxadtures that supxadport elecxadtric fields of 10-100 MV/m, esxadpexadcialxadly at the start of the acxadcelxaderxadaxadtor chain where cexadramxadic inxadsuxadlaxadtors are used for very high graxaddixadent DC guns. These inxadsuxadlaxadtors are difxadfixadcult to manxaduxadfacxadture, rexadquire long comxadmisxadsionxading times, and often exxadhibxadit poor rexadlixadaxadbilxadixadty. Two techxadnixadcal apxadproachxades to solvxading this probxadlem will be inxadvesxadtixadgatxaded. Firstxadly, inxadvertxaded cexadramxadics offer soxadluxadtions for rexadduced graxaddixadents bexadtween the elecxadtrodes and ground. An inxadvertxaded dexadsign will be prexadsentxaded for 350 kV, with maxxadixadmum graxaddixadents in the range of 5-10 MV/m. Secxadondxadly, novel cexadramxadic manxaduxadfacxadturxading proxadcessxades will be studxadied, in order to proxadtect triple juncxadtion loxadcaxadtions from emisxadsion, by apxadplyxading a coatxading with a bulk rexadsisxadtivxadixadty. The proxadcessxades for crexadatxading this coatxading will be opxadtixadmized to proxadvide proxadtecxadtion as well as be used to coat a cexadramxadic with an apxadproxadprixadate graxaddixadent in bulk rexadsisxadtivxadixadty from the vacxaduxadum side to the air side of an HV standxadoff cexadramxadic cylinxadder. Exxadamxadple inxadsuxadlaxadtor dexadsigns are being comxadputxader modxadelled, and inxadsuxadlaxadtor samxadples are being manxaduxadfacxadtured and testxaded