TL BA CA CUO THIN FILM SRF CAVITY

THE USE OF SUPERCONDUCTING RADIO FREQUENCY (SRF) CAVITIES IN ELECTRON ACCELERATORS CAN BE DRAMATICALLY EXTENDED WITH THE UTILIZATION OF HIGH TEMPERATURE SUPERCONDUCTORS (HTSC). WITH CRITICAL MAGNETIC FIELDS OF APPROXIMATELY 11,000 OE AT 2K OR 4 TIMES NIOBIUM, HTSCS OFFER THE POTENTIAL OF ACCERLERATING FIELDS OF 200 MEV/M WHICH WOULD SIGNIFICANTLY IMPROVE THE PERFORMANCE OF ELECTRON AND HEAVY ION LINACS. ALTERNATIVELY, COMPARABLE ACCERLERATING FIELDS COULD BE ACHIEVED AT 77K WITH LIQUID NITROGEN COOLANT SIMPLIFYING ACCERLERATOR OPERATION. UNFORTUNATELY, HTSC PROCESSING TECHNIQUES HAVE NOT BEEN DEVELOPED WHICH AREAMENABLE TO COATING COMPLEX SHAPES SUCH AS THE INSIDE OF CYLINDRICAL CAVITIES. RECENT WORK AT ATM INDICATES THAT METALORGANIC CHEMICAL VAPOR DEPOSITION (MOCVD) AND PLASMA ENHANCED CVD ARE USEFUL HTSC THIN FILM PROCESSING TECHNIQUES THAT COAT CONFORMALLY. COUPLED WITH THE IDENTIFICATION OF A SUITABLE HIGH THERMAL CONDUCTIVITY SUBSTRATE IT SHOULD BE POSSIBLE TO DEMONSTRATE THE FEASIBILITY OF FABRICATING A THIN FILM HTSC ACCELERATOR CAVITY. THE GOAL OF PHASE I IS TO DEPOSIT TLBACACUO FILMS ON SILVER SUBSTRATES WITH A RS- 100 UOHMS AT 77 K, 1 GHZ AND 100 OE WHICH REPRESENTS A SIGNIFICANT IMPROVEMENT OVER OXYGEN FREE HIGH CONDUCTIVITY COPPER CAVITIES. PHASE II WOULD EXTEND PERFORMANCE AS WELL AS PROVIDE A PROTOTYPE HTSC MICROWAVE ACCELERATOR CAVITY.