LBL superconducting accelerator developments

The superconductivity program of LBL is reviewed. The major elements of the overall program are: 1) pulse dipoles for superconducting accelerators, 2) transport (dc) magnets for beam lines, 3) fundamental and material studies, and 4) cryogenics for refrigeration, cryostats, transfer lines, operation, etc. Ten pulsed dipoles with winding internal diameter of 7.5-10cm and physical length of 40-45cm have been built and tested. The first 8 magnets have been reported previously. ''Identical'' dipoles number 9 and number 10 were built simulataneously as a test of the reproducibility of the fabrication technique used. Short and long multipole measuring coils were used at power and audio frequencies at 3000K, 770K, and 4.20K. Overall, 2 magnets were ''identical'' to about the limit of the present measurement precision. A superconducting beam line consisting of one dipole in one cryostat followed by a quadrupole doublet in a second cryostat has been in operation at the Bevatron since 1973. Both cryostats are fed from one CTI model 1400 helium liquefier-refrigerator of closed cycle mode. Runs longer than 40 days have become routine, and entire operation is carried out by the personnel operating Bevatron. Pulse and transport magnets use multicore NbTi superconductor in copper. Most recent conductor tests have included wires with 3000 filaments of each 5 μ diameter, and cable made from wires with 1345 filaments of each 3 μ diameter. (Iwakiri, K.)