Update on ALICE-LHC interfaces & BCM Technical Forum, 25/03/10 Antonello Di Mauro Status of data exchange Cogging with BPTX and BPIM FW upgrade BCM response and thresholds studies Outlook

Status of data exchange List of parameters to be published via DIP to LHC fully reviewed (EDMS LHC-OP-ES-0018), some data are also displayed in the LHC_Config and LHC_Operation Vistar pages DIP directory name Description Source dip/ALICE/LHC/ExptStatus State of experiment (STANDBY, PHYSICS, ...) DCS dip/ALICE/LHC/BKGD Background monitoring BCM, SPD, V0 dip/ALICE/LHC/IntensitiesPerBunch Arrays of bunch intensities BPTX/BPIM dip/ALICE/LHC/Luminosity Total instantaneous lumi. [cm-2s-1] + coll. rate V0-AND dip/ALICE/LHC/LumiPerBunch Instantaneous b-by-b lumi. [cm-2s-1] dip/ALICE/LHC/LumiScan Coll. rate, errors, integration time SPD, V0-AND, ZDC dip/ALICE/LHC/FillLumi Total delivered and recorded lumi / Fill [cm-2] dip/ALICE/LHC/LuminousRegion H, V and centroid, tilt angles HLT, SPD dip/ALICE/LHC/AbortGap No. of protons in the abort gap in each beam dip/ALICE/LHC/Handshake Injection, Adjust and Beam-Dump HS states dip/ALICE/LHC/Timing/BPTX1 or 2 Phase, wrongBucket-flag and wrongBucket-array dip/ALICE/LHC/Timing/BPTX DeltaT of colliding bunches (shift from IP=0) 25/03/10 ALICE-LHC Interfaces

Status of data exchange All selected data from LHC subsystems and instrumentation published over DIP (machine configuration parameters and status, BLM, BPM, BCT, collimators, vacuum gauges) retrieved, treated and transferred by DCS to OCDB Treatment (smoothing) of data necessary to reduce memory load but also to fulfill other requirements (correlations between ALICE and LHC data,…) New project for online data analysis tool (G. De Cataldo) 25/03/10 ALICE-LHC Interfaces

Status of data exchange PVSS Distrib. Sys. OFFLINE HLT LOCAL archive OCDB FXS DIM LHC-ALI_DCS LHC ECS DIP DIM BPTX V0 T0 ZDC SPD PIT BCM PM ……. PVSS Distrib. Sys. V0_DCS V0_DCS DIM V0_DCS ACR-DISPLAY CTP From G. De Cataldo 25/03/10 ALICE-LHC Interfaces

Cogging with BPTX and BPIM FW upgrade Using scope and BPIM boards (from LHCb) to readout BPTX signal BPIM FW developed by E. Scapparone, only for triggering in 2009, phase measurements (BPTX1-BC1, BPTX2-BC1, …) done with scope BPTX arrival time difference used to calculate collision coordinate, LHC RF adjusted to set Z~0 BPTX-1 – IP2 = 146085.5 mm BPTX-2 – IP2 = 145361.5 mm (DTOF = 2.922 ns) BPTX-1 cable delay = 800.4 ns BPTX-2 cable delay = 670.8 ns Estimated offset DT(B1-B2)= 126.678 ± 0.200 ns BPTX-C (on beam-2) BPTX-A (on beam-1) 25/03/10 ALICE-LHC Interfaces

Cogging with BPTX and BPIM FW upgrade 23 Nov 2009 Beam-1 bucket 1 Beam-2 bucket 8911 Without cable+ beam TOF estimated delay correction 126.678 ns -> Measured Vertex Z = -1.3 cm 25/03/10 ALICE-LHC Interfaces

Cogging with BPTX and BPIM FW upgrade ATLAS CMS Measured vertex Z used to x-check/calibrate DT offset, corrected value: 126.820 ns 25/03/10 ALICE-LHC Interfaces

Cogging with BPTX and BPIM FW upgrade New FW (from LHCb, adapted by E.Scapparone) installed in BPIM readout boards, producing: bunch-by-bunch intensity filling scheme check (ghost bunches, wrong bucket) abort gap phase shift (B1-BC1, B2-BC2) DT(B1-B2) (z coordinate of IP) Commissioning in progress (in collaboration with LHCb), triggering working as usual, publication of bunch-by-bunch to be optimized 25/03/10 ALICE-LHC Interfaces

BCM response and thresholds studies MKI injection failures can produce TDI grazing resulting in large splashes reaching ALICE TDI grazing events produced by TDI setting up (jaws scan) or MKI delay scan have been used to check BCM response and estimate fluxes in ALICE 68,6 m 78,1 m 25/03/10 ALICE-LHC Interfaces

BCM response and thresholds studies BCM-A 8 sensors z = + 6 m, r = 10 cm BLM-MWBMD BCM C 7 sensors z = -18.5 m, r=10 cm

BCM response and thresholds studies Beam dump logic: Fast abort on RS1 (integration over 40 ms) or RS2 (integration over 80 ms) coincidences: dump the beam if 3 adjacent diamond sensors out of 4 show a current > thrRS1 or thrRS2 , respectively Slow abort on RS32-Sum (1.28 ms): Sorting out the two highest and the lowest of 8 sensors, dump the beam if RS32-Sum > thrRS32 Doses from misinjected beam were presented in ALI-INT-2001-003, updated by B. Pastircak in 2008 providing fluences in subdetectors. For BCM-A grazing on pilot bunch, fluence ~ 104-105 /cm2 25/03/10 ALICE-LHC Interfaces

BCM response and thresholds studies MKI delay scan BCM threshold 4000 nA Beam dump in 3 turns 200 nA 25/03/10 ALICE-LHC Interfaces

BCM response and thresholds studies BCM response: 100 part/cm2 ~ RS2: 1 nA Fluence from FLUKA simulation: 2 x 10-5 /p 1 pilot bunch (5x109 p)-> 105 part/cm2 ~ 1000 nA, as observed during the MKI delay scan, consistent with BLM response RS1 ~ 0.5 Gy/s (using conversion factors: 5.4x10-6 C/Gy , 2x10-15 C/part, 60 cm2 area) 4x72 bunches of 2x1011 -> 109 part/cm2 ~ 10 mA Proposed thresholds: RS1: 1500 nA, RS2: 750 nA -> ~ 5-7 x 105 part/cm2 RS32: 200 nA -> background ~ 500 part/cm2 25/03/10 ALICE-LHC Interfaces 13

Outlook BCM system instability on Post-Mortem events thoroughly checked, fixed with patches in PVSS and new simple procedure for shifter; further improvements to be discussed Implementation of BLM dedicated panel for shifter HW emergency buttons (ALICE-> SAFE, Beam-Abort) Implementation of Safe-Machine Flags from GMT (HW signals, not via DIP) to control transitions SAFE <-> NOT-SAFE Background monitoring (online and offline) dedicated effort 25/03/10 ALICE-LHC Interfaces