ADT fast losses MD

The fast beam losses in the order of 1 ms are expected to be a potential major luminosity limitation for higher beam energies after the LHC long shutdown (LS1). Therefore a Quench Test is planned in the winter 2013 to estimate the quench limit in this timescale and revise the current models. This experiment was devoted to determination the LHC Transverse Damper (ADT) as a system for fast losses induction. A non-standard operation of the ADT was used to develop the beam oscillation instead of suppressing them. The sign flip method had allowed us to create the fast losses within several LHC turns at 450 GeV during the previous test (26th March 2012). Thus, the ADT could be potentially used for the studies of the UFO ("Unidentied Falling Object") impact on the cold magnets. Verification of the system capability and investigations of the disturbed beam properties were the main objectives of this MD. During the experiment, the pilot bunches of proton beam were excited independently in the horizontal and vertical planes to induce beam losses on the primary collimators (TCPs). An asymmetrical configuration of collimator jaws provided losses on only one side of an aperture. This created the conditions of a 3-corrector orbital bump Quench Test which is planned for winter 2013. The temporal loss distribution and the loss duration at 4 TeV were determined. The impact of the phase advance between the ADTs and TCPs was investigated at 450 GeV.