The Cosine Two Theta Quadrupole Magnets for the Jefferson Lab Super High Momentum Spectrometer

The Jefferson Lab 12 GeV/c upgrade involves building a new 12 GeV/c spectrometer for JLAB´s Hall C called the super high momentum spectrometer (SHMS). This device achieves 4.5 mStr acceptance at bend angles for 5.5 to 40 by using five magnetic elements in a DQQQD configuration. The Q1 quadrupole is described elsewhere in this conference and is an evolution of a cold iron magnet used previously for the existing JLAB 7.5 GeV/c high momentum spectrometer (HMS). The pair of identical cosine two theta quads are an entirely new design with a large 60 cm warm bore and 13 T/m gradient. These 5 T Quads provide focusing for particles from 1 to 12 GeV/c and have an integral gradient strength of 23.5 (T/m)m. The magnetic design, including multipole strengths, will be presented. The quadrupole cold mass uses a stainless steel shrink fit force collar, titanium keys and a copper stabilized superconductor consisting of a 36 strand surplus SSC outer cable wave soldered to a copper extruded substrate. This combination provides for a very conservative magnet that can be assembled with little or no tooling and a high degree of stability. The force collar mechanical analysis will be presented as well as details of the magnet cryostat.