LHC BI 2015 Summary: BSRL M. Palm (BE-BI-PM)

Changes since Run 1 Optical line BSRL and BSRA on extension table Hybrid detectors installed Both beams since TS2 TS3 Hybrid shutter control installed Additional layer of protection against saturation APD Synchrotron light BSRA Hybrid

APD: Performance Distorted bunch profile “Phantom” bunches “Phantom” bunch signal typically decreases during the fill Mechanism not fully understood… Possible cause: bias voltage ripple (>GHz) leading to sensitivity fluctuations and avalanche onset.

Hybrid: Intended use (1) Doublets Satellites Doublet train, B1 (Fill 4164) vdM-scan: Ghost & Satellite fraction Hybrid significantly better than APD Flattop

Hybrid: Intended use (2) B1 Satellite & Ghost map (vdM scan, Aug 25) =Filled/masked bucket Abort Gap

Hybrid: Bonus Abort gap populationSynchronous phase shift, Bunch by bunch

(No baseline subtraction) Raw Beam loss correction Hybrid: Unexpected Most likely beam losses(?) Bunched signal from wrong beam corrupts measurement …can be corrected Long term damage? Profile of opposite beam is detected B1 structure seen by B2 hybrid

Outlook Install BSRL equipment on removable breadboard YETS Current location New location? Fibre

Backup Hybrid abort gap estimate and measured beam loss