As part of the program to build and test SSC 50mm aperture prototype dipole magnets, a series of seven full-length (15m-long) dipoles were built and tested at BNL. The design of these magnets and their differences from the earlier 40mm aperture dipole magnets have been discussed elsewhere[1]. In order to thoroughly evaluate the performance of the new design, an extensive and varied schedule of tests were done, and these included quench testing and stress measurements to exhibit mechanical and thermal behavior, a ramp rate quench program to study eddy current heating effects in the conductors, and a multitude of magnetic field measurements to characterize field quality.

Several 1.8-m-long magnets have been built to evaluate possible variations in the design of the Superconducting Super Collider (SSC) dipoles. Except for length and the parameters being tested, these models have the features of 40-mm-aperture collider dipoles, which are based on a two-layer cosine theta coil. In these magnets, all-Kapton cable insulation and the effects of changes in the axial coil prestress have been tested. Construction details and test results for quenching, field harmonics, and coil loading are reported.<>

A series of 1.8m SSC dipoles is being built and tested as part of the R&D program. One of the 40 mm — aperture magnets was tested with a standard assembly and then reassembled and retested in a special configuration which had significantly less azimuthal prestress than the initial assembly. We report quench, coil stress, end force, and harmonics data for each of the assemblies. Quench performance was not degraded for the low-prestress assembly.

A new measurement of the anomalous magnetic moment (G-2 factor) of the muon to a precision of 0.35 p.p.m. is being undertaken with the AGS at Brookhaven National Laboratory. It will involve a precision superferric storage ring with a magnetic field of 1.5 T and a radius of 7 m for 3.1 GeV/c muons. The magnetic field in the storage region must be homogeneous to one part in 106 and the effective field averaged around the ring must be known to 1 part in 107. The design status of the superferric storage ring and of the techniques planned for magnetic-field control and measurement are presented. Perturbation field calculations for the iron and coil configuration, considerations on the superconducting coil, shimming and measurement techniques, and plans for a test magnet program are discussed.

Five R&D dipole magnets have been assembled with different levels of tangential prestress applied to the windings. Four magnets have trained beyond the ISABELLE 5T operating field. Three have trained to the short sample limit of the superconducting braid. The two magnets with the highest level of tangential prestress required the fewest training quenches to reach 5T. The training history of these R&D magnets is better than that of the eleven industrial magnets. Two of the industrial magnets were trained beyond 4.5T; the others reached fields in the range 3.8T to 4.2T. The industrial magnets had generally lower levels of prestress than the R&D magnets and differed in other important respects as well. These changes were designed to reduce the heat generated by conductor motion due to Lorentz forces. Construction of magnets with the present design has eliminated the largest part of the training quenches seen in the industrial series of magnets.

A precise measurement of the anomalous g value, a = (g - 2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result aμ+ = 11 659 202(14)(6) × 10-10 (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The measurement tests standard theory and has the potential to discover new physics. The analysis of data collected in 2000 and 2001 is well underway and, when combined with data from a requested and final run in the fall of 2002 and winter of 2003, are expected to reduce the experimental uncertainty on aμ to 0.4 ppm.