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Signals between LHC Machine & ALICE: an Update

Signals between LHC Machine & ALICE: an Update. David Evans ALICE TB 23 rd February 2006 (with input from Detlef Swoboda). Update Since December. 13 th Dec 05: data exchange requirements presented to ALICE TB

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Signals between LHC Machine & ALICE: an Update

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  1. Signals between LHC Machine & ALICE:an Update David Evans ALICE TB 23rd February 2006 (with input from Detlef Swoboda)

  2. Update Since December • 13th Dec 05: data exchange requirements presented to ALICE TB • 25th Jan 06: meeting at CERN to discuss issues (D. Evans, C. Fabjan, P. Vande Vyvre, L. Jirden, F. Carena.) • 6th Feb 06: Leade meeting at CERN to discuss draft LHC document on data exchange. (EDMS: 701510) D. Evans

  3. Data Interchange Concept • DIP/DIM (data interchange protocol) • Publish/Subscriber paradigm • All data with UTC time stamp • 250 kBytes & 100 messages/s • Dominated by LHC Cryo Machine bandwidth • Latency about 1 s D. Evans

  4. Experiments  LHC (ATLAS/CMS) Minimum data set D. Evans

  5. Can ALICE Supply this Information ? • Luminosity • Can we get an estimate from T0, V0, CTP interaction rate ? • Position and size of luminous region • Can we get these data from V0 online ? D. Evans

  6. LHC  Experiments D. Evans

  7. Data base Sub-dets DCS LHC Data S/W Interlocks Data Exchange Dim/Dip DCS already uses DIM/DIP concept so LHC data exchange already fits into this system. DCS to take care of data exchange and software interlocks. N.B. S/W interlocks not for Beam Dump. Data written to database so no need for special end-of-run event to store these data. D. Evans

  8. Beam Interlock System (BIS) • H/W link from USER to Beam Dump System: beam dump request. • H/W interface supplied by machine • Radiation monitors and connection to H/W interface to be supplied by ALICE • Use ATLAS/CMS radiation detectors • Marc Tavet to coordinate this. • ALICE to find resources. D. Evans

  9. Beam Dump Request • ALICE Beam monitors (for Beam Dump interlock) must send their status to CCC via DIP. • E.g. on a scale: 1 (safe)  5 (abort) • Post-Mortem needs to be sent to CCC after beam dump request. • Can be sent via email within 24 hours (no automated system required). D. Evans

  10. LHC Injection Inhibit • No solution yet • H/W solution safest but requires machine to find resources and design system. Also ALICE would have to produce extra hardware. • S/W solution easiest if safe solution can be found i.e. exps have to continually submit signal in case of network problems. • Probably best solution. D. Evans

  11. Beam Synchronous Timing Message (BST) • BST uses the TTC technology, to send messages over channel B of TTC. • Machine supplies optical cable but NOT interface. • Message mainly used by LHC instrumentation etc. • Some messages maybe of interest to experiments. D. Evans

  12. Portion of BST Message for Experiments D. Evans

  13. BST and ALICE • BST message not guaranteed when no beam • No hardware available to take BST data. • Not possible to stamp events with data without major upgrade of trigger and all sub-detector front-end electronics. • All important information also send via other means (DIP/DIM, Safe LHC Parameter system (SLP). • CTP, DAQ consider system is not needed. • Optical cables installed, however, in case we want it in the future. D. Evans

  14. ALICE Magnets • CCC to control ALICE magnets • Magnets connected to LHC BIS • Status of magnets monitored by CCC and sent via DIP data exchange. • ALICE has requested ability to control our magnets after beam is dumped. • Control passed back to CCC prior to ramping. D. Evans

  15. ZDC • ZDC to be moved out during beam injection stage. • ZDC has its own H/W interlock. • ZDC to be moved in & out of data taking position from ALICE Control Room (Not CCC). • Status of ZDC to be sent to CCC via DIP. D. Evans

  16. Coordination of LHC-Detector Exchange • Detlef Swoboda has agreed to coordinate these exchange issues between the machine and experiments (thanks to Chris Fabjan’s proposal). • This means each detector will only have to talk to one person rather than many. • Detlef has already put forward a strategy. D. Evans

  17. LDX Implementationby D. Swoboda • Proposed Strategy • Nominate contact • Experiment • LHC machine (actually will be several for machine!) • Prioritize parameter list in order to have at least the compulsory systems ready at LHC start up • Identify equipment required + equipment supplier • Define WPs for implementation • Experiment • LHC machine • Assign required resources D. Swoboda @ ALI TB

  18. Other News from Leade • LHC physics will begin with 75ns bunch crossing rate – can’t say how long, weeks ? • Experiments request they go to 25ns asap. • To minimise pile-up in detectors. • Collision rate monitors for ALICE agreed • Use ionisation chambers D. Evans

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