A twin aperture resistive quadrupole for the LHC

The European Organization for Nuclear Research (CERN) is constructing the L arge Hadron Collider (LHC). The LHC's cleaning insertions require 48 twin a perture resistive quadrupoles.: These 3.1 m long magnets have a gradient of 35 T/m for an inscribed circle of 46 mm diameter and an aperture separatio n distance of 224 mm. This magnet project is part of the Canadian contribut ion to the LHC. A prototype magnet was delivered in May 1998 and measured a t CERN. Design changes were made based on the results. Due to the small ape rtures and the complicated geometry, the mechanical precision of the lamina tions and stacks is the main issue in the production of these quadrupoles. Series production will start-in October 1999. The design and the measuremen t results are described in this paper.