Long superconductor fibers have been continuously produced by electrophoretically depositing REBa2Cu3O7−x (where RE=Y or a selected rare-earth element) powder onto a metal substrate fiber and sintering, then electrophoretically depositing silver and sintering. After collecting the coated fiber on a take-up spool, the entire spool is batch-oxygenated to form the 90 K superconducting phase. Multiple fibers are then continuously unspooled and soldered into a copper channel to form the final multifilamentary high-temperature superconductor wire. Superconducting fibers over 1000 m long and multifilamentary wire 70 m long have been produced.

A dc and pulsed-mode 75 keV proton injector has been developed and is used in characterization of a continuous-wave 6.7 MeV, 100 mA radio-frequency quadrupole (RFQ). The injector is used frequently at the full RFQ design power (100 mA, 6.7 MeV) where the RFQ admittance (1 rms, normalized) is 0.23 (π mm mrad). The injector includes a 2.45 GHz microwave proton source and a beam space-charge-neutralized, two magnetic-solenoid, low-energy beam-transport system. The design RFQ beam transmission of 95% has been demonstrated at 100 mA RFQ output current.

No abstract

Melt texture processing of YBa 2 Cu 3 O y is limited by the slow cooling rate and the high temperatures required. Changing the rare earth can improve the processing conditions. The melting point of YbBa 2 Cu 3 O y can be reduced below the melting point of silver by adding silver, Yb 2 BaCuO 5 and/or reducing the oxygen partial pressure. The recrystallization rate of NdBa 2 Cu 3 O y + 0.2Nd 4 Ba 2 Cu 2 O 10 is shown to be extremely rapid. For low values of x , solid solutions of (Yb 1−x Nd x )Ba 2 Cu 3 O y may be able to be melt processed rapidly below the melting point of silver.

No abstract