Conduction Cooling and Fast Recovery in MgB2-Based DC Resistive SFCL

The feasibility of a conduction-cooled MgB2-based superconducting fault-current limiter with fast recovery is investigated. A real-scale device for a distribution network is considered. The dc resistive con\ufb01guration is chosen in order to avoid ac losses and to allow conduction cooling. A high-heat-capacity cable is speci\ufb01cally developed in order to cope with the requirement of fast recovery. A short-length sample of the cable is manufactured in order to assess its feasibility. The detailed design of a prototype is also carried out, and the performance is numerically investigated

Manufacturing aspects of the ATLAS barrel toroid double pancakes

In 1999 INFN (Istituto Nazionale di Fisica Nucleare) ordered to ANSALDO the manufacturing of 16 double pancakes for the ATLAS BARREL TOROID. In July 2001 four Double Pancakes have already been completed and shipped to the integration site. In this paper the main aspects of the manufacturing of the largest superconducting coils ever built (5*25 m) are described. The main phases of the manufacturing procedure are reviewed starting from the conductor preparation to the VPI impregnation, including references to the materials used as well as to the relevant customer's requirements. In particular the special winding form and the winding technique are treated. For each phase the most critical aspects and the relevant solutions are pointed out. Particular details about the technical solutions adopted for the impregnation and curing of the Double Pancake, which could not be performed inside an autoclave due to the huge dimension of the coil itself, are reported. Finally the methods used for the dimensional and electrical tests are described and the results obtained on the first double pancakes are analyzed. (4 refs)

Compact Superconducting High Gradient Quadrupole Magnets for the Interaction Regions of High Luminosity Colliders

Recent developments in the high luminosity e(+)e(-) colliders are based on a collision scheme with a large Piwinski angle, a vertical beta function beta(y) much smaller than the bunch length, and a crab waist transformation. This scheme is being adopted in the SuperB asymmetric collider, to be built in Italy, with a design peak luminosity of 10(36) cm(-2) sec(-1). A crucial role is played by the quadrupole doublets QD0/QF1, which are placed close to the interaction point and generate gradients close to 100 T/m. The available space for the doublets is very small, causing the magnets to be operated with a high engineering current density (2000 A/mm(2)). Starting from the helical coil concept, an advanced design of the quadrupole has been developed. The paper discusses the basic design concepts and the development of a coil model aimed at assessing the design criteria and demonstrating the feasibility of the quadrupole. The successful test of the coil model opens the way to new compact superconducting high gradient quadrupole magnets for the interaction regions of high luminosity colliders

A MgB2 superferric racetrack magnet

A magnesium diboride, cryogen-free, H-dipole magnet with cold iron yoke was constructed and tested. The racetrack coil, 48 cm long, was wound with 350 m of nickel-clad, copper-MgB2 tape. The iron yoke forms a 2.6 cm gap. The magnet was connected to a cryocooler and tested at different temperatures ranging between 8.5 and 24 K. The maximum current, 263 A, was reached, without training, at 8.5 K. The corresponding field in the gap was 2.35 T