An Ultra-Narrow, High-Quality, High-Field Quadrupole Magnet

An ultra-narrow, high-quality quadrupole magnet has been designed for use in the Bevatron experimental area. Several magnets have been fabricated and tested. Pertinent dimensions are: aperture = 8.244", core width × height × length = 12" × 24" × 24", overall width × height × length = 13" × 41" × 32" (including adjustable stand, terminals and water manifolds but excluding supply and return piping). This corresponds to a width/aperture ratio of ~ 1.5 compared to previously reported "narrow" ratios of 2.5 to 3.0 and common ratios of 5 or more. This narrow magnet permits significant improvement in beam target utilization by permitting more beam lines and/or moving closer to the target to achieve greater particle acceptance. In spite of its small size, the magnet can achieve field gradients up to 5000 G/in.. The measured field quality generally equals or betters that of full-size quads, which is surprising considering the ultra-narrow width and the simple hyperbolic pole shape. A compact cooling circuit arrangement contributed to achievement of these results within such a small volume.