Mechanical Design, Assembly and Testing of a Support Structure for LARP Nb$_3$Sn Quadrupole Magnets for LHC

A support structure for the 120 mm Nb$_3$Sn quadrupole magnet is presently under development for use in the upgrade for LHC at CERN. The design aims to build on existing technology developed in LARP with the LQ and HQ mag- nets and to further optimize the features required for operation in the accelerator. The structure and the proposed assembly methods include features for maintaining mechanical alignment of the coils to achieve the required field quality. It also includes a helium containment vessel and provisions for cooling with 1.9 K helium. The development effort includes the assembly of a 15 cm model to verify required coil load is achieved. Status of the R&D; effort and an update on the magnet design, including its incorporation into the design of a complete one meter long cold mass is presented.