MBRD Prototype Cold Tests: Mechanical Stability and Performances

The High-Luminosity upgrade of the Large Hadron Collider (LHC) foresees the replacement of magnets around the interaction points of the ATLAS and CMS experiments. One of these is the recombination dipole MBRD (Main Bending Recombination Dipole), or D2. It consists of a cosine-theta magnet, double aperture with same polarity, wound with a Nb-Ti Rutherford cable, featuring a central field of 4.5 T, a magnetic length of 7.78 m and a 105 mm bore (diameter). In this paper we present the test results of the full-length prototype with a special focus on the mechanical measurements. The prototype has been instrumented with tens of strain gauges to monitor the mechanical behaviour and to allow for a comparison to the finite elements model of the magnet, to achieve a firm interpretation of the collected data in view of the series construction. In this contribution, the most important collected data will be shown, and compared with simulations results, giving a precise description of the mechanical performances of the prototype, with an outlook to the construction of the series magnets.