Primo (e ultimo ?) giorno di fascio a LHC
Nuovo Logo di CMS
valido almeno fino alla
prossima primavera:
Beam Splash: ~2.109 protons on collimator ~150 m upstream of CMS
ECAL- pink; HB,HE - light blue; HO,HF - dark blue; Muon DT - green; Tracker Off
Other Distributions: Beam Dumped in Coll.
Energy in ECAL (EE-, EB, EE+)
CMS Week Sep08
4
First Events: Beam going through CMS
Halo Muons in CSCs and HB
Beam Pickup (ch1) CMS Beam
Condition Monitors (ch 3, 4)
CMS Centre Meyrin
Point 5 Control Room
CMS Week Sep08
5
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 61642
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
18/12/2015
7
MB2 Occupancy
MB3 Occupancy
MB4 Occupancy
Phi asymmetry
Correlation DT – EB energy
Beam halo in DT
DT and first beams:beam halo
--- All SLs
--- r-ϕ SLs
--- r-z SLs
beam halo muons
cross few cells of r-ϕ
SLs but many cells in r-z
MB1 occupancy: # digis/SL
18/12/2015
15