Author: K., K.
Paper Title Page
THPFI052 Application of Atmospheric Plasma-sprayed Ferrite Layers for Particle Accelerators 3406
 
  • F. Caspers, M. Betz, S. Federmann, M. Taborelli
    CERN, Geneva, Switzerland
  • K. K., C.A.M. Schulz
    Surface Engineering Institute, RWTH Aachen University, Aachen, Germany
  • J.X. Wu
    IMP, Lanzhou, People's Republic of China
 
  A com­mon prob­lem in all kind of cav­ity like struc­tures in par­ti­cle ac­cel­er­a­tors is the oc­cur­rence of RF-res­o­nances. Typ­i­cally, fer­rite plates at­tached to the walls of such struc­tures like di­ag­nos­tic de­vices, kick­ers or col­li­ma­tors, are used to dampen those un­de­sired modes. How­ever the heat trans­fer rate from these plates to the walls is rather lim­ited. Braz­ing fer­rite plates to the walls is not pos­si­ble in most cases due to the dif­fer­ent ther­mal ex­pan­sion co­ef­fi­cients. To over­come those lim­i­ta­tions, at­mos­pheric plasma spray­ing tech­niques have been in­ves­ti­gated. Fer­rite lay­ers with a thick­ness from 50 mi­cron to about 300 mi­cron can be de­posited on metal­lic sur­faces like stain­less steel ex­hibit­ing good ther­mal con­tact and still rea­son­able ab­sorp­tion prop­er­ties. In this paper the tech­no­log­i­cal as­pects of plasma de­po­si­tion are dis­cussed and re­sults of specif­i­cally de­vel­oped RF loss mea­sure­ment pro­ce­dures for such thin mag­net­i­cally lossy lay­ers on metal are pre­sented. This kind of lay­ers can also be ap­plied for the pro­duc­tion of high tem­per­a­ture RF power loads and re­lated ex­am­ples will be shown.