Comparison of LHC Beam Loss Maps Using the Transverse Damper Blow Up and Tune Resonance Crossing Methods

The LHC collimator settings are qualified regularly via beam loss maps. In this procedure, the beam is artificially excited to create abnormal loss rates. The transverse damper blow up (ADT) and tune resonance crossing methods (QT) are used to increase the betatron amplitude of particles and verify the efficiency of the collimation cleaning hierarchy in IR7. This paper presents a quantitative comparison of the methods, for the qualification of the collimator settings at different operating points in the LHC machine cycle. The analysis is done using Beam Loss Monitor (BLM) with integration times of 1.3 s and 80 ms, the latter being available as from the 2012 run onwards. We present here the use of the faster BLM data (80 ms) to study the time evolution of the losses in IR3 and IR7 during offmomentum loss maps.