Cored rutherford cables for the GSI fast ramping synchrotron

Abstract

Abstract-The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 200T-m and 100T.m. Fast ramp times are needed, which can cause significant problems for the magnets, particularly in the areas of s c loss and field distortion. This paper discusses the 200T.m ring, which will use Cos0 magnets based on the RHIC dipole design. We discuss the reasons for choosing Rutherford cable with a resistive core and report loss measurements carried out on cable samples. These measurements are compared with theoretical calculations using measured values of inter-strand resistance. Reasonably good agreement is found, but there are indications of non-uniformity in the adjacent resistance R,. Using these measured parameters, losses and temperature rise are calculated for a RHIC dipole in the operating cycle of the accelerator. A novel insulation scheme designed to promote efficient cooling is described.Index Terms--ac loss, dipole magnet, field error, superconducting synchrotron, Rutherford cable.

Rapid-cycling dipole using block-coil geometry and bronze-process Nb₃Sn superconductor

“…The calculations follow closely the work of Wilson [7]. Table 1 presents the calculated ac losses for each design for a 1 T/s ramp rate.…”

Magnetic and Thermal Characteristics of a Model Dipole Magnet for the SIS 300

“…Values of contact resistances in the cable are: crossover resistance and adjacent resistance [4]. For the calculations of matrix losses, the following expression for transverse resistivity (corresponding to in the copper) was used:…”

A SMES-Based Power Supply for Accelerator Magnets

“…The conductor used in this application would also be suitable for the SMES magnets [4], [5]. The Rutherford cable developed for this application would have a typical loss around 47 mJ per meter of cable in the case that the SMES operates with 1 T/s; in case of a failure of one of the four SMES modules the ramping speed would increase to 1.17 T/s and the losses to 62.3 mJ/m cable.…”