Primo (e ultimo ?) giorno di fascio a LHC Nuovo Logo di CMS valido almeno fino alla prossima primavera:

Beam Splash: ~ protons on collimator ~150 m upstream of CMS ECAL- pink; HB,HE - light blue; HO,HF - dark blue; Muon DT - green; Tracker Off

CMS Week Sep084 Other Distributions: Beam Dumped in Coll. Energy in ECAL (EE-, EB, EE+)

CMS Week Sep085 First Events: Beam going through CMS Beam Pickup (ch1) CMS Beam Condition Monitors (ch 3, 4) Point 5 Control Room CMS Centre Meyrin Halo Muons in CSCs and HB

First LHC Beam in DT System

DT and first beams: beam splash 17 events induced by beam 1 dump on the collimators observed in run DT are far from being the best tool to detect first beams events. Max number of hits/TDC = 16 in the DAQ. For splash events all TDC are fired -> >300 hits in inner stations. No segment reconstruction if > 50 hits -> no segments reconstructed in inner stations. 100% of the MB1 chambers illuminated in all 17 events 22/02/20147

MB2 Occupancy

MB3 Occupancy

MB4 Occupancy

Phi asymmetry

Correlation DT – EB energy

Beam halo in DT

DT and first beams:beam halo 22/02/ MB1 occupancy: # digis/SL --- All SLs --- r-ϕ SLs --- r-z SLs beam halo muons cross few cells of r-ϕ SLs but many cells in r-z