DEVELOPMENT OF A NIOBIUM SUPERCONDUCTING RF QUADRUPOLE LINAC

THE DEVELOPMENT OF SUPERCONDUCTING RADIO FREQUENCY (RF) ACCELERATOR STRUCTURES HAS PRIMARILY FOCUSSED ON HIGH ENERGYELECTRON ACCELERATORS AND HEAVY ION BOOSTERS FOR ELECTROSTATIC ACCELERATORS. HOWEVER, SEVERAL GROUPS HAVE SUGGESTED THAT THIS TECHNOLOGY MIGHT BE USED TO ACHIEVE A CONTINUOUSLY OPERATING RADIO FREQUENCY QUADRUPOLE (RFQ) ACCELERATING STRUCTURE. THE NORMALLY CONDUCTING RFQ LINEAR ACCELERATOR (LINAC) IS A PROVEN ACCELERATING STRUCTURE WIDELY USED FOR RESEARCH AND INDUSTRIAL APPLICATIONS. RECENT TESTS OF A SUPERCONDUCTING NIOBIUM RFQ-LIKE DEVICE ATARGONNE NATIONAL LABORATORY (ANL) INDICATE THAT SUPERCONDUCTING RF TECHNOLOGY MAY APPRECIABLY EXTEND THE RANGE OF DESIGN OPTIONS FOR THE RFQ LINAC. THE INITIAL MEASUREMENTS AT ANL, WHILE NOT PERFORMED WITH AN OPTIMIZED DESIGN FOR A SUPERCONDUCTING RFQ, RESULTED IN THE ACHIEVEMENT OF ELECTRIC SURFACE FIELDS GREATER THAN 100 MV/MAT CAVITY CHARGE VALUES GREATER THAN 10(8), WITH ELECTRON LOADING BEING THE FIELD-LIMITING PROCESS. THE SUCCESSFUL DEVELOPMENT OF A SUPERCONDUCTING RFQ LINAC OFFERS SIGNIFICANT ADVANTAGES FOR BASIC SCIENCE RESEARCH AND FOR MEDICAL AND INDUSTRIAL APPLICATIONS REQUIRING EFFICIENT PRODUCTION OF CONTINUOUS BEAMS. THE OBJECTIVE OF THIS STUDYIS TO GENERATE THE DESIGN OF AN OPTIMIZED SUPERCONDUCTING RFQ LINAC USING THE NIOBIUM TECHNOLOGY AND EXPERTISE AVAILABLE AT ANL. THIS PHASE I STUDY ADDRESSES THE SIGNIFICANT DIFFERENCES BETWEEN THE DESIGN CRITERIA FOR A SUPERCONDUCTING RFQ STRUCTURE AND THOSE FOR A NORMAL CONDUCTING RFQ STRUCTURE, AS REVEALED BY THE ANL TEST RESULTS. THE IMPACT OF SUPERCONDUCTING RFQ TECHNOLOGY ON ACCELERATORS FOR NUCLEAR PHYSICS AND FOR MEDICAL AND INDUSTRIAL APPLICATIONS IS BEING STUDIED, AND A NIOBIUM RFQ STRUCTURE OPTIMIZED FOR SUPERCONDUCTING OPERATION IS BEING DESIGNED FOR DEMONSTRATION AT ANL DURING PHASE II OF THIS PROJECT.