Conductor Placement Research Articles

A superferric dipole magnet proposed for use in the superconducting super collider

A dipole magnet employing superferric technology has been designed at the Texas Accelerator Center for use in the SSC. This magnet has a maximum central field of 3.0 T and the multipole components are of the order of one part in 10000. Because of the relatively low peak field the forces exerted on the conductors are correspondingly low and the problem of maintaining the conductor placement at high field is minimized. Since the steel provides approximately 1.7 T, the magnet is also fairly insensitive to small errors in the placement of the conductors. These factors contribute to making a magnet which can be mass produced at a relatively low cost.

A New Accelerator Superconducting Dipole Suitable for High Precision Field

Work on superconducting dipoles for accelerators started about twelve years ago in several High Energy Physics laboratories. At present, many problems have been solved and three big superconducting synchrotrons or storage rings are under construction : the "Doubler" and "Isabelle" in the USA and "UNK" in the USSR. In Europe, the DESY Laboratory in Hamburg is studying the "HERA" project (not yet approved). All these projects use dipole fields in the range of 4 to 5 teslas in coil bores of 75 to 130 mm in diameter. However, these magnets still raise difficulties and their required field quality remains hard to achieve due to the high level of accuracy needed in conductor placement. In this paper a new design is proposed to improve this accuracy. Models along this design are being developped at Saclay, requiring a quite novel technology, whose advantages and possible difficulties are reviewed.

Magnetic Field Measurements on ISABELLE Storage Ring Magnets

In 1978 the magnetic field shapes of six ISABELLE prototype dipole magnets were measured in detail. All the harmonic terms that are forbidden by symmetry in dipole magnets are found to have values that are zero to within the allowed tolerances. This result indicates that the random errors in conductor placement are within tolerances and that the assembly techniques are satisfactory in this regard. However, the first allowed error term in a dipole magnet, the sextupole term, is much too large, and varies greatly from magnet to magnet resulting in field errors at the edge of the desired good field region that are 10-3 of the central field value, whereas the tolerable field errors are of the order of 10-4 of the central field value. This large sextupole term has been traced to assembly errors which yield a coil assembly which instead of being circular in cross section is racetrack shaped, with the vertical axis being 10 to 20 thousandths of an inch greater than the horizontal axis. This problem will be corrected in the future production series.