Diffusion and Halo Population Measurements with Collimator Scans at 6.5 TeV

Beam halo measurements at 6.5 TeV in the LHC were conducted via collimator scrapings in an MD carried out on the 4th November 2015. From the time evolution of the beam losses in a collimator scan, it is possible to extract information on the halo diffusion and population. Six scans were performed with two collimators in the vertical and horizontal planes in B1 and B2 respectively. The scans were done with squeezed, separated beams, with colliding beams and once again with separated beams but with a gentle continuous transverse blow-up with the ADT. The results obtained were compared with those from similar scrapings performed in a MD in 2012 at 4 TeV.