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A scheme is proposed for dealing with thermo-hydraulic quench simulation in superconducting magnets.

An analysis is presented of results of the Segregated Copper Ratio Experiment on Transient Stability (SeCRETS), which has been completed in the SULTAN facility.

The MITHRANDIR 2.1 was used in joint + conductor thermal-hydraulic experiments and analyzed of a full size joint sample.

A model currently used in the thermo-hydraulic code Gandalf has been enhanced and adapted to cable in conduit conductors with central cooling channel.

An analysis of the stability of the International Thermonuclear Experimental Reactor's Torodial Field and Central Solenoid superconducting magnets is presented. The study, conducted using the code Gandalf, revealed that the energy margins were well over the expected disturbances. The observed instances of dual stability, present in some cases but disappears with integration time step refinement, is indicative of the importance of a detailed convergence study.

A set of routines, also called a 'Flower,' was designed and integrated to the code Gandalf. The routines were aimed at providing a simple model of the hydraulic connections to a cryogenic plant of a coil that utilizes cable-in-conduit conductors that have central cooling channels. 'Flower,' validated against experimental data from Quench Experiment on Long Length in the CRPP facility SULTAN, is shown to be capable of simulating hydraulic boundary conditions.

The Paul Scherrer Institute is studying a synchrotron radiation source, the Swiss Light Source, for a variety of applications in physics, chemistry, material sciences and industrial production. Specially optimized superconducting bending magnets will provide the hard X-rays necessary for structure analysis and micro-fabrication. This preliminary design study investigates a combined function magnet system with dipole and quadrupole coils, for bending and focusing of the electron beam. The electromagnetic characteristics of the magnet, including the end effects, are studied in 2-D and 3-D analyses. The proposed concept is feasible to satisfy the requirements of field strength and quality in the envelope of specifications, while an optimization of the coil geometry is recommended to improve the longitudinal magnetic characteristics.

EDIPO is the new 12.5 T superconducting test facility that is being installed at CRPP in Villigen, Switzerland. It will be placed beside the existing test facility SULTAN. The main purpose of both facilities is testing Nb3Sn samples for the ITER project. EDIPO will provide a uniform high field region of \sim1 m, i.e. longer than SULTAN's (\sim45 cm). EDIPO includes the main magnet and a superconducting transformer to power it with a current up to 100 kA in the test sample. The energy stored in the dipole is 16 MJ and in the undesired event of a quench this energy must be safely extracted. A Quench Detection System (QDS) is required to trigger the quench protection system for both the dipole and the transformer. This paper describes the overall QDS from the conceptual design, components, manufacture and commissioning as well as interactions with related systems. [ABSTRACT FROM PUBLISHER]

A spare, 3.5 m long dual-channel cable-in-conduit conductor (CICC) section, made according to the most recent hER toroidal-field coil design, allowed conducting dedicated thermo-hydraulic experiments in the SULTAN test facility. The sample was heated by eddy-current losses induced in the strands by an applied AC magnetic field as well as by strip heaters mounted on the outside of the conductor jacket. Temperature sensors mounted on the jacket surface, in the central channel and at different radii in the annular region revealed a detailed picture of the temperature distribution at different mass flow rates and heat deposition modes. A clear phenomenological description of the temperature deviations from the one-dimensional expectation emerged during the experiments. The measurement of the flow velocities in the central channel and in the annular region under several heat-load conditions led to further insights. [ABSTRACT FROM AUTHOR]

Pressure drop in the ITER PFCI cable-in-conduit conductor (CICC) has been measured at CRPP using pressurized water at room temperature. The PFCI conductor is a dual channel CICC and the coolant flows in parallel in the central channel and in the annular bundle region. In our experiment the flow in the central channel is blocked and the longitudinal friction factor of the annular bundle region is deduced from measurements of pressure drop and mass flow rate. Two conductor samples are investigated, one with and one without subcable/outer cable wraps. The results show that the wraps have a negligible effect on the friction factor, and that the Katheder correlation overestimates the actual friction factor. [ABSTRACT FROM AUTHOR]

A high order finite difference scheme is introduced to deal with thermo-hydraulic quench simulation in superconducting magnets, specifically in the case of cable-in-conduit conductors (CICC). Liquid helium flow in CICC is governed by the unsteady convection-diffusion conservation equations, in the low Mach number and high Reynolds number flow region. In the past several years many methods have been considered for quench simulation in superconducting magnets, for example, finite element, finite volume, and finite difference methods. One of the main challenges is the accurate simulation of flow during a superconductor quench, given the large gradients in pressure and temperature that arise during conductor normalization. These simulations are key to proper magnet protection design. The Dispersion Relation Preserving (DRP) scheme is applied to the quench simulation problem. The computational results are compared to those obtained using a well-proven commercial quench simulation code (Gandalf), as well as experimental data. Preliminary results are promising. [ABSTRACT FROM AUTHOR]

Abstract: In the last few years, the critical current densities of long commercially available REBa2Cu3O7−x (RE-123, where RE represents Y or a rare earth element) coated conductors have reached values of 250A/cm-width at 77K and zero applied field. Even higher values of 600A/cm-w (77K, B =0) have been demonstrated in shorter lengths. The attractive features of the use of these high-T c superconductors (HTS) are operation temperatures above 20K and/or magnetic fields higher than those envisaged for the ITER TF coils. Possible operation conditions for HTS fusion magnets have been studied taking into consideration the possible further improvements of RE-123 coated conductors. Investigations of stability and quench behavior indicate that stability is not a problem, whereas quench detection and protection need attention. Because of the high currents necessary for fusion magnets, many tapes need to be assembled into a transposed conductor. The qualification of HTS conductors for fusion magnets would require their test at magnetic fields of 11T and currents well above 10kA. The possibilities to test straight HTS conductor samples in SULTAN have been considered. For a test at 4.5K, only the development of a low resistance joint between the HTS conductor under test and the NbTi transformer of SULTAN would be necessary. Tests up to 20K would require that the HTS sample is connected with the NbTi transformer by a conduction-cooled HTS bus bar of large thermal resistance similar to the HTS module of a current lead. HTS conductor tests at temperatures around 50K would be possible with modified cryogenics. [Copyright &y& Elsevier]