Design, Performance and Series Production of Superconducting Trim Quadrupoles for the Large Hadron Collider

The Large Hadron Collider (LHC) will be equipped with several thousands of superconducting corrector magnets. Among the largest ones are the superconducting trim quadrupoles (MQTL). These twin-aperture magnets with a total mass of up to 1700 kg have a nominal gradient of 129 T/m at 1.9 K and a magnetic length of 1.3 m. Sixty MQTL are required for the LHC, 36 operating at 1.9 K in and 24 operating at 4.5 K. The paper describes the design features, and reports the measured quench performance and magnetic field quality of the production magnets. The MQTL magnet production is shared between CERN and industry. This sharing is simplified due to the modular construction, common to all twin-aperture correctors

Design, Manufacturing and Preliminary Tests of a Conduction Cooled 200 kJ Nb-Ti micro-SMES

A superconducting magnet with 200 kJ stored energy and 75 kW output/input power has been designed and manufactured. The device, which is aimed to power quality enhancement in electric grid, consists of two coaxial coils, counter-series connected in order to keep the stray field below the limit of 0.5 mT. The SC wire is a copper stabilized Nb-Ti strand. Several copper slabs are placed within the coils in order to permit heat removal deep inside the coil, thus allowing cryogen-free cooling and operation at high AC losses regime. Several tests with different ramp rate have been carried out at the liquid helium temperature. Design and manufacturing characteristics as well as test results are discussed in this pape

Electron transport properties of MgB

We report measurements of the resistivity, $\rho ,$ and the Seebeck coefficient, S, of a MgB2 sintered sample, and compare S with theoretical calculations based on precise electronic structure calculations. $\rho$ is fitted well by a generalized Bloch-Grüneisen equation with a Debye temperature $\Theta _{R}$ of 1050 K. S is given by the sum of a diffusive and a phonon drag term and the behavior in the temperature region T_{\rm c}<T<0.1\Theta _{R} follows the relationship AT+BT3. The phonon drag term indicates a strong electron-phonon interaction. The diffusive term, compared with calculations, suggests that $\sigma$ bands give the main contribution to the Seebeck effect

Electron transport properties of MgB2 in the normal state

none9We report measurements of the resistivity, rho, and the Seebeck coefficient, S, of a MgB2 sintered sample, and compare S with theoretical calculations based on precise electronic structure calculations. rho is fitted well by a generalized Bloch-Gruneisen equation with a Debye temperature circle minus(R) of 1050 K. S is given by the sum of a, diffusive and a phonon drag term and the behavior in the temperature region T-c < T < 0.1circle minus(R) follows the relationship AT + BT3, The phonon drag term indicates a strong electron-phonon interaction. The diffusive term, compared with calculations, suggests that sigma bands give the main contribution to the Seebeck effect.M. PUTTI; E.GALLEANI D'AGLIANO; D.MARRÈ; F.NAPOLI; M.TASSISTO; P.MANFRINETTI; A.PALENZONA; C.RIZZUTO; S.MASSIDDAPutti, Marina; GALLEANI D'AGLIANO, Enrico; Marre', Daniele; F., Napoli; M., Tassisto; Manfrinetti, Pietro; A., Palenzona; C., Rizzuto; S., Massidd

Design of the Superconducting AC and DC Distribution for the ASCEND Demonstrator at Airbus

The ground-based Advanced Superconducting and Cryogenic Experimental power train Demonstrator (ASCEND) at Airbus intends to demonstrate the potential and feasibility of a cryogenic and superconducting powertrain as a breakthrough electric propulsion solution on future electric aircraft. A direct current distribution network is used in a propulsion chain to transfer 500 kW of power from the source to an electrical converter, which transforms the power into an alternating voltage/current to drive a superconducting motor. The working point of 1,700 A and 300 V is chosen for safety and installation reasons by operating at relatively low voltage. The direct current (DC) bus of ASCEND will be formed by a pair of high-temperature superconducting CORC cables inserted into a 10-meter-long narrow cryostat, resulting in a compact and lightweight solution. The 2-meter-long alternating current (AC) bus between the inverter and the electric motor is formed by a three-phase CORC cable. The challenge associated with 500 Hz operation in which a balance between AC loss in the cable and the size and mass of the system needs to be found, will be outlined. The AC and DC buses include several devices that connect the liquid nitrogen cooled power cables with the other system components that, in the case of the room temperature generator, operate at significantly higher temperatures. These devices thus include conduction-cooled current leads that are dimensioned to minimize the heat inleak from the warm to the cold environment. An overview of the design of the AC and DC buses and connecting devices will be provided and some of the design and operational challenges will be outlined.</p