Angular alignment of LHC injection protection stopper

Machine safety depends critically on the correct setup of the protection elements. One of the injection protection elements consists of exceptionally long jaws (4 m). An angular offset of the jaws could affect significantly the measured beam size and, as a consequence, the correct setup with respect to the beam. Dedicated studies and cross-calibrations have been performed to quantify the effect of tilts and offsets on the setup of this stopper and to check the provided passive protection.