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Sensitivity tests of BLM_S chamber in PSB dump. (Detector for very high radiation areas of LHC ). What is BLM_S. Low sensitivity BLM pumped to approx. 10 -5 torr Based on Secondary Electron Emission from Ti electrode Placed mainly in the Collimation areas, close to IPs, LHC Dump etc….
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Sensitivity tests of BLM_S chamber in PSB dump (Detector for very high radiation areas of LHC ) AB/BI D.Kramer
What is BLM_S • Low sensitivity BLM pumped to approx. 10-5 torr • Based on Secondary Electron Emission from Ti electrode • Placed mainly in the Collimation areas, close to IPs, LHC Dump etc… APC meeting
Interior of Secondary Emission Beam Loss Monitor APC meeting
Geant4 Simulation ResultsSecondary Emission Yield0.057 e-/primary @ 1.3GeV
Geant4 Simulation ResultsSEY vs. TiSignal electrode thickness Beam line SEM screens BLM_S
Installation in the PSB dump line BLM_S Screen ACEM Rad Hard camera APC meeting
2005 PSB measurements APC meeting
Comparison with results from PSI 250MeV continuous proton beam APC meeting
2006 Measurements in PSB dump • Modified BLMS installed on the movable stage 19/4 • 1st data taken 4/5 with up to 250e10 protons/bunch (AD user) • maximum intensity allowed by the BLM system • Access due to HV contact 10/5 APC meeting
Linearity of the SEM response in 2006 APC meeting
Simultaneous measurement with SEM and ACEM (PS BLM)equivalent to ~ 1e19 MIPs/s
Quench and Damage Levels Quench level and observation range 450 GeV 7 TeV BLMS* & BLMC Damage levels Dynamic Arc: 108 Collimator: 1013 Special & Collimator1 turn Arc 2.5 ms APC meeting
Summary • SEY from the first measurements in 2006: (5 ± 0.3)% • Good agreement with 5.7% from Geant4 • No more problems with linearity • Sufficient time response • HV scan to be done (we need ~2h beam time) APC meeting