Status of the LHC Beam Instrumentation: - PowerPoint Presentation

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2. Status of the LHC Beam Instrumentation:Diamond BLMs, BPM, DOROS, BSRT, WS, BGV7th EVIAN WORKSHOP - December 2016G. TRAD2G. Trad on the behalf of BE-BIAcknowledgments:S. Bart Pedersen, G. Bau, E. Bravin, M. Gasior, R. Jones, F. Roncarolo, J. Olexa, T. Lefevre, C. Xu, C. Zamantzas

3. OverviewdBLMBPM/DOROSWSBGVBSRT/I/HG. TRAD3Experience in 2016LimitationsUpgrades in EYETS7th EVIAN WORKSHOP - December 2016

4. 47th EVIAN WORKSHOP - December 2016G. TRADNormal IC BLM Integrated current signal (min integration window 40us)Diamond BLMs are complementary devices for beam loss diagnose in ns range time resolutionresolving single bunch level beam loss signalHigh dynamic range 3-4 ord. of magnitudePrimary collimatorsBeam extractionB2 injectionB1 injectionAbort GapReadoutRosy Box by CividecLeCroy OscilloscopeHistogram mode: 1.25Gs/S, 256MS buffer, the FPGA determine the signal above the thr. or not with a time bin width of 1.6nsWaveform mode: 5Gs/S, 1GS bufferWaveform mode: 200KS, sampling @ 1nsFESA class existing Data stored in PostMortemPython script for device configuring and data storing (EOS server). GUI for data offline viewing.Diamond Beam Loss Monitors

5. 57th EVIAN WORKSHOP - December 2016G. TRADF. Burkart, O. Stein, et alMeasurementsBig Interest in :Integrating the diamonds in the control systemeasing access and use of the diamonds data Injection Lossesns losses observedAllowing injection losses diagnostic, understanding the sourceBbyB Losses at the TCPsFast UFO busting?Tentative Abort Gap monitoringNot enough sensitivityDiamond Beam Loss Monitors

6. 67th EVIAN WORKSHOP - December 2016G. TRADDiamond Beam Loss MonitorsStandardisation of the dBLMs readout: VFC based acquisition system adopted (fast sampling, aiming for 1GS/s, presently ~ 600M) OUTLOOK=> Restarting after EYETS with same infrastructure : Scopes linked to FESA and Rosy boxesThe BbyB losses waveforms acquired for every injection with the LeCroys through FESAAre available to be “displayed” in the IQCHowever meaningful only if thresholds are setFirmware being developedFinal checks for specificationsOnce available, replace both the LeCroy Scopes and the Rosy BoxesTests system foreseen in lab, SPS(BA1) and LHC (parallel to existing RO) to validate full chain performanceHopefully, few changes from FESA side profiting of synergies with fBCT readout development.Relatively easy deployment of the electronics for all diamonds, once validation is completed.

7. 77th EVIAN WORKSHOP - December 2016G. TRADBeam Position Monitors Wide Band Time Normaliser Reminder: WBTN electronics and Firmware allowing: 1) Asynchronous “Orbit” acquisition mode Average beam position over “t” sec 2) “Synchronous Orbit” acquisition mode Average selected “bunch” position over “t” sec 3) “Capture” Acquisition mode Bunch by Bunch and turn by turn position over “T” turnsUsed in the orbit feedbackWas put in operation for operating with asymmetric beam intensities (p/Pb)Used in optics measurementsAnd IQC

8. 87th EVIAN WORKSHOP - December 2016G. TRAD Wide Band Time NormaliserIn 2016 deployed new firmware, featuring:“Capture” / “Orbit” conflict solved,Improved synchronization handling => More reliable “Capture”Improved resolution in “Orbit” mode (better averaging with more bits)“Synchronous Orbit” acquisition enabledImproved stability and maintainability FESA adaptations to new FWBeam Position MonitorsIssues:Issues during the ions Run when trying “Synchronous Orbit” due to not optimal bunch selection (presence of encounters) and LSA settings.Residual problems in “Capture” acquisition;Some diagnosed to absence of BST triggers -Impact of BST reboot affects a lot of BI instruments-New diagnostics to be put in place to monitor the BST Others, De-phasing still not fully understood.Dancing BPMs: spurious orbit reading (electronics issue seems to be solved by exchanging cards; new diagnostics put in place)

9. 97th EVIAN WORKSHOP - December 2016G. TRADBeam Position Monitors - DOROSDiode ORbitand OScillation systemDifferent way of processing BPM signals DOROS deployed for Q1 around all IPs and in some collimators jaws(2 more collimators coming in 2017)Developed to provide accurate beam position measurements for collimator BPMsOptimised for position resolution, absolute accuracy for centred beamsBetter S/N for orbit measurementResolution ~ 0.1µmNo bunch-by-bunch measurementIncludes an oscillations channel, provide phase measurement for continuous local beta-beat calculation with very low oscillation amplitudes

10. 107th EVIAN WORKSHOP - December 2016G. TRADExcitation with 20MHz filters, amplitude 0.4ADTgain : H=-7.5dB / V=-14.5dBMachine tunes : 0.31/0.32 Excitation tunes : 0.29/0.30Excitation pattern : 1000-20000-1000 turnsDamper : OFF.Osc. Amplitude : ~350um in HBeam Position Monitors - DOROSFrom FESA, synchronized acquisition of the “capture“ mode with the ADT excitationWill minimize excitation time to what is just needed to measure the couplingSpectra comparison between WBTN and DOROS

11. 117th EVIAN WORKSHOP - December 2016G. TRADBeam Position Monitors - DOROSMore intelligent FESA class control that will adjust the automatic gain control thresholds according to the beam mode,Investigations to prevent this with:-trying to develop precise model to compensate the nonlinearities with a polynomial correction -by shifting the Q1 BPM signals electrically towards the centre with nice attenuators. (can be tried one another DOROS in parallel)Lack of reproducibility (fill to fill) mainly caused by lack of adequate control of the system parametersNon linearity observed when the gains are adjusting to accommodate to the amplitude drop caused by the intensity decay. Effect reproduced and quantified in lab;Relative change in signal amplitude w.r.t to the dynamics of the ADC induce fake orbit drifts and is clearly enhanced by beam offset to BPM centre.

12. 127th EVIAN WORKSHOP - December 2016G. TRADBeam Gas Vertex Detector - DemonstratorUse tracks from beam-gas interactions to reconstruct beam spotProvide bunch-by-bunch size with a 5% resolution within 5 minuteProvide average σ with absolute accuracy of 10% within 5 minuteStatusDetector fully commissioned (Dead channels ≤ 1%)SciFi detector planes, Trigger, Read-out, CPU farm, Control & DAQ SWObserved rate of events matches expectationsGas injection system operationalData-taking campaigns during 2016 under various beam conditions in parallel to operation and in dedicated MDBGVFirst DataVertex distribution along the gas target chamberNext StepsTriggers to be improved (adding L0 confirm?)Offline analysis for high precision track & vertex reconstructionImplement analysis software in CPU farm for real-time meas.Establish data logging and measurement publishing towards CCC

13. 137th EVIAN WORKSHOP - December 2016G. TRADWireScannersLHC emittance reference measurements throughout the cycleUsed mainly for BSRT calibrationIntensity/energy limitations (protons) ~240b @ Inj, ~12b @ FT (limits for ions to be rechecked)accurate, online precision limited better precision in offline analysis (position reading / background)EnergyLumiβ*Turn Mode acquisition deactivated -> improved noise background only on B1Beams are becoming small for B2H, Accuracy questionable for emittance <1 micron (less than 2 point per sigma)Alternative technique for Wire position measurement during scan will be tested in EYETS to validate absolute scale of the readings.Based on interferometers, usually used for measuring collimator gaps

14. 147th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRTBSRT on Fesa 3Profiles Logging on demand binary filesBSRT calibration is now taking place in the intensity ramp ups fills (3x3 -> 10x10 fill)LDM in good shape used during VdM fillsOverall Satisfactory performanceDigital cameras and new intensifiers to be installed in EYETS, (If Soft Ready) ~200 frames per second =>some 50 bunches/sBig Intervention of the HW-> all optics removed for table mounting changeM.Hostettler

15. 157th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRTB1V @ 6.5 TeV3 Cross-Calibration this year: April-August-OctoberAugust Calibration was “fishy” still investigatingAll calibrations made such as no data loss even if a calibration goes wrong This year observed a dependence of the calibration on the beam mode @ 6.5 TeVOptical system and magnification linked to slope and offset of  Investigate bigger spread on B1 emittances (Observations correlated with beam behavior?)Study dependence of the calibration on machine conditions, optics/ beam modes

16. 167th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRIOnly way to accurately measure very small beams!2D interferometer will be adopted.In 2017 :Interferometry alignment to be improved to allow parallel measurements with BSRT.calibrate to WS at FT and check stability and validate accuracy and precision In 2016 a measurement campaign to qualify the instrument -> Good agreement with WS at Injection. -> deep analysis of all systematics at FT.

17. 177th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRHPrototype coronagraph for halo diagnostics installed in LHCFirst measurements taken during machine development periodsFirst ever beam halo measurement with coronagraph at 450 GEVOptimization ongoing at 6.5TeV for correct interpretation of the observationParasitic light at 6.5TeV observed and needs to be understoodContrast of 2x10-3 already demonstrated with early tests at 450GeV

18. Contrast of 2.10^-3 demonstratedBigger disk would have allowed going to higher contrastCoronagraph images during controlled blow-upCoronagraph images during controlled scraping6th HL-LHC Collaboration Meeting, Paris, Nov 2016 Rhodri Jones (CERN)18Synchrotron Radiation Monitors - BSRH

19. SummaryOther BI changes foreseen in 2017 (not covered in this talk)

20. 207th EVIAN WORKSHOP - December 2016G. TRADThank you for your attention!

21. 217th EVIAN WORKSHOP - December 2016G. TRADDiamond Beam Loss Monitorshttp://indico.cern.ch/event/527597/contributions/2159806/https://indico.cern.ch/event/475993/contributions/1986089/https://indico.cern.ch/event/467516/contributions/1987257/attachments/1226757/1796348/Diamond_BLM_electronics_and_software.pdfhttps://indico.cern.ch/event/451797/contributions/1947869/attachments/1189896/1727067/20151119_BITB_status_dBLMs_ostein.pdfhttp://accelconf.web.cern.ch/AccelConf/ibic2013/papers/mopc45.pdfhttp://cds.cern.ch/record/2141809/files/mopty058.pdfhttp://cds.cern.ch/record/2131864/files/CERN-ACC-2016-0011.pdfhttps://indico.cern.ch/event/402868/contributions/1846191/attachments/1159433/1668594/20150924_injection_losses_section_meeting.pdf

22. 227th EVIAN WORKSHOP - December 2016G. TRADBeam Position Monitorshttp://cds.cern.ch/record/2207315/files/mopmr029.pdfhttp://cds.cern.ch/record/2063000/files/CERN-ACC-NOTE-2015-0033.pdfhttps://indico.cern.ch/event/491203/contributions/1169028/attachments/1227474/1797788/160212_DOROS_SW_Olexa.pdfhttp://ibic2016.vrws.de/papers/mopg07.pdfhttp://cds.cern.ch/record/1546401/files/CERN-ATS-2013-038.pdf?subformat=pdfahttp://cds.cern.ch/record/2056602/files/CERN-ACC-Note-2015-0029%20MD.pdfhttps://indico.cern.ch/event/467516/contributions/1987259/attachments/1226719/1796259/LHCinterlockBPMupgrade.pdfhttps://indico.cern.ch/event/506059/contributions/1184318/attachments/1247396/1837685/BPM_cal_LBOC22032016.pdf

23. 237th EVIAN WORKSHOP - December 2016G. TRADspares

24. 247th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRSSSlit ScannerFull machine profiles acquisition in few hundreds of msecInstalled in Parallel to the interferometry line2017 dedicated lineOptimization of the read out system still ongoingEM coupling Noise issue solvedWireBeamSecondariesShowerScintillatorLightPMTBunch by BunchProfileBeamSynchrotronRadiationOpticsBeam ImageSlitPMTBunch by BunchImage ProfileCalibrationBunch by BunchProfileAnalogyWire ScannerSR Slit Scanner

25. 257th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRSS~700 bunchesMeasured 3 times 200 ms/ measStill to be calibrated

26. Beam Current Change Monitor System Status December 2016BCCM systems have been running “operationally” on both Beam 1 and Beam 2 fast BCTs since Summer 2016Connected to BIC but beam interlock not activatedFESA, Logging and Post Mortem availableBeam 2 systemHas run reliably throughoutSmall spikes due to sensitivity to RF clocks traced to FIR filter in FPGANo impact on dI/dt detection – well below interlock thresholdWill be fixed for 2017Beam 1 systemSuffers from large intermittent spikesAppear only during stable beams with high intensityNo activity during ion runWould trigger a dump if the system were “active”Visible on both the BCCM system and new digital FBCT acquisition systemClear indication that this is EMI either level of the detector, cabling or rackInvestigations ongoing to try and solve this during EYETS

27. Examples of Spikes Observed on Beam 127Spikes as seen by BCCMAs seen by BCCM Post Mortem following “Dump” caused by SpikeAs seen by new digital Fast BCT acquisition system on bunch by bunch measurements

28. 287th EVIAN WORKSHOP - December 2016G. TRADBeam Position Monitors - DOROSDOROS and WBTN show similar beam offsets when 2 beams passes at the same time.Larger offsets when the beams have opposite positions in the vacuum chamber. Intensity imbalance worsens measurement of low intensity beam.DOROS performs better than standard BPM system also for the directional couplers (dual beam BPMs)Temporal offset needed for having position readings independent of other circulating beam : 3ns DOROS and >7 ns WBTN

29. 297th EVIAN WORKSHOP - December 2016G. TRAD Wide Band Time NormaliserBeam Position MonitorsfBCT signals and BPM readings to recognize filling pattern of circulating beam.Validated at the end of 2016 run, available for 2017Old algorithm still available if problems arise.BPM Phase-In with multiple bunchNo more need to have only 1 bunch in a ring to check/correct phase-inMay diagnose/fix phase-in problems during injections

30. TimedBLM with ROSY® ReadoutTime-Loss-Histogram: precise beam loss timing counts 9/16/2016oPAC Topical Workshop - Barcelona301.6ns+1+1+1+1+1+1

31. Time-loss-histogram with ROSY®9/16/2016oPAC Topical Workshop - Barcelona31LHC full machine with 2076 bunchesB1 TCP12b48b96binjection gap88.9 usabort gapb2crosstalk

32. Point 6

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34. Beam oscillations with DOROS12/13/2016Document reference34ObsBox cross-check of signalExcitation with 20MHz filters, amplitude 0.4ADT H gain: -7.5dBADT V gain: -14.5dBMachine tunes: 0.31/0.32 Excitation tunes: 0.29/0.30Excitation pattern:1000-20000-1000 turnsDamper is OFF.Oscillation amplitude: ~350um in HValidated by OMC team to measure coupling

35. 357th EVIAN WORKSHOP - December 2016G. TRADCourtesy: O. Stein et alPt 7 TCPsProvide integrated loss histogram L = f(time in turn) at regular intervals (50 Hz?) with a time resolution better than 200MHz (5 nsec bunches from SPS)• System should detect losses of less than ~1E7 protons (low/high gain) LHC Injection areas• Provide losses = f(time) with fast ext/inj (TTL/BST) trigger pulse for off-line analysis with a sampling rate above ~500MHz for at time covering at least 10 turns (a few N *100.000 values)• System should detect losses of ~1E7 protons (low gain / high gain channels)• Used for SPS extraction / LHC Injection Checks (software interlock?)• Data provided every extraction/injection to the post-mortem data server SPS/LHCDiamond Beam Loss Monitors

36. 367th EVIAN WORKSHOP - December 2016G. TRADDiamond Beam Loss MonitorsCourtesy: M. ValettePoint6:2 Diamonds, one for each beam, for asynchronous dump study:Data digitized by Lecroy Scope and recorded through FESA. Data from beam2 dBLM was not fully understood and will be further studied by TE/MPE next year with a MD.Estimate number of nominal bunches hitting the dump collimator in case of asynchronous beam dumpPreliminary results from a MD experiment (courtesy of M. Valette):Pilot(7e9)Nominal (~3e10)Work in progress for quantitative analysis (signal calibration & data processing tools)

37. Diode ORbit and OScillation system (DOROS)DOROS is a novel beam position measurement system based on diode detectorsThe system has been developed to be used with new LHC collimators and some of the most important LHC BPMs (mostly Q1 BPMs in IP1,2,5,8)The front-ends contain two parallel subsystems which share the same RF processing:DOR – diode orbit processingoptimised for sub-micrometre resolution and micrometre precisioncost 1: bandwidth limited to some 100 Hzcost 2: not bunch-by-bunch, it measures an “average”DOS – diode oscillation processingoptimised for processing of small beam oscillations in the bandwidth 0.05 – 0.5 frevcost 1: orbit information removed from the processingcost 2: signals not in mm and changing with beam intensityBlock diagram of two channels of a DOROS front-end processing signals from one pair of BPM electrodes:LPF – low-pass filter, TSG – test signal generator, PGA – programmable gain amplifier, FGA – fixed gain amplifier, CDD – compensated diode detector, ODD – oscillation diode detector, OSP – oscillation signal processing.

38. Diode Orbit partMeasuring orbits in the frequency range 0 – 100 Hz limited by analogue low-pass filtersEach BPM electrode signal processed by a dedicated diode detectorCancellation of the residual asymmetry in the analogue processing of the signals from opposing BPM electrodes with periodic signal multiplexing (1 Hz rate)Processed electrode signals sampled simultaneously with 24-bit ADCs at the LHC frev Real-time UDP streaming of the processed ADC data from the DOR channelsRaw electrode data IIR filtered, decimated and sent to a FESA server at a 25 Hz rate Cut-off of the IIR filter can be programmed in the range 0.01 Hz – 2 kHz.FESA server computes DOR data and absolute beam orbits in mm;they are published at 1 Hz rate with 1 s latency.Data is logged and available in TimberA faster asymmetry calibration switching is under study to reach data rates and latency compatible with the current orbit feedback operation (12.5 Hz)Electrode ADC samples decimated to the 1/20 of frev and stored in the front-end memory. They are used in two ways:On-demand “Capture mode” :Triggered by FESA commands or dedicated Beam Synchronous Timing (BST) eventData can be used to compute orbit spectra in the bandwidth 0 – 250 HzRecords up to some 6 million turns (300 k DOR “decimated” ADC samples)Current FESA limit is 100 k turnsPost-mortem rolling buffers:Controlled by FESA commands or BSTBuffer depth 800 k turns (40 k DOR samples)DOROS in a nutshell

39. Diode Oscillation partOptimised diode detectors for measuring small beam oscillations in 0.3 – 0.5 kHz frequency rangeProcessed analogue signals sampled simultaneously with 24-bit ADCs at the LHC frevADC data from oscillation channels stored locally in the front-end memory at the sampling rate without decimation. The DOS data is stored in parallel to the DOR data. On-demand “Capture mode” :Triggered by FESA commands or dedicated BST eventRecords up to some 6 million turns Current FESA limit is 100 k turnsPost-mortem rolling buffers:Controlled by FESA commands or BSTBuffer depth 800 k turnsThe DOS data is foreseen to undergo real-time synchronous detection performed in the system FPGA to obtain directly the oscillation amplitudes and phases. This way the oscillation processing can be based on very long data sets to increase the system sensitivity without the need of storing raw data. The synchronous detection can be done at two separate frequencies to measure also local betatron coupling. The resulting amplitudes and phases (just a few numbers) can be sent along with the orbit data. Sampling of the ADCs in each DOROS front-end can be synchronised to the BST or BPM beam signalsDOROS in a nutshell

40. 407th EVIAN WORKSHOP - December 2016G. TRADSynchrotron Radiation Monitors - BSRIFixed Slit Separation (Hyp. Gaussian)σ is analytically derived:Slit Separation Scanning Modef(x) is obtained by applying an inverse Fourier transf. of the resulting curve Γ(D)Inverse Fourier Transformation,Obtain profileE=6.5 TeVλ= 560 nm +/- 5 nmExpo= 1msD: 3mm -> 12 mma=1.5 mmh=0.5 mmFilter : ND1

41. 417th EVIAN WORKSHOP - December 2016G. TRADWireScannersUsed mainly to calibrate the BSRT and in MDsLimits to be reviewed for ions at least1 wire broken in 2016 spare in use on B2VTurn Mode acquisition deactivated -> improved noise background only on B1Beams are becoming small for B2HAccuracy questionable for emittance <1 micron (less than 2 point per sigma)Alternative technique for Wire position measurement during scan will be tested in EYETs to validate absolute scale of the readings.

42. 427th EVIAN WORKSHOP - December 2016G. TRADWireScannersLHC emittance reference measurement throughout the cycleUsed mainly for BSRT calibration and MDsIntensity/energy limitations (protons) ~240b @ Inj, ~12b @ FT (limits for ions to be rechecked)accurate, online precision limited better precision in offline analysis (position reading / background)Turn Mode acquisition deactivated -> improved noise background only on B1Beams are becoming small for B2H, Accuracy questionable for emittance <1 micron (less than 2 point per sigma)Alternative technique for Wire position measurement during scan will be tested in EYETs to validate absolute scale of the readings.Based on interferometers, usually used for measuring collimator gaps

43. SPS transverse beam size diagnostics review 09/11/2016

44. SPS transverse beam size diagnostics review 09/11/2016

45. SPS transverse beam size diagnostics review 09/11/2016

46. SPS transverse beam size diagnostics review 09/11/2016