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Beam-Gas Vertexing as an LHC diagnostics device: an overview. Motivation Concept Plamen will give details about design parameters (rates, acceptance, , etc.) Organization More in Bernd’s talk. LHC emittance measurement. Neglecting dispersion, the beam size is given by size
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Beam-Gas Vertexing as an LHC diagnostics device: an overview Motivation Concept Plamen will give details about design parameters (rates, acceptance, , etc.) Organization More in Bernd’s talk
LHC emittancemeasurement • Neglecting dispersion, the beam size isgiven by size 2 = where = X or Y (H or V) opticsfunction emittanceThis iswhatisneeded! • = usually taken from machine model + optics measurements • = measured from various devices: • Wire Scanners (WS) • Synchrotron light monitors (BSRT) • Beam-gasionization monitors (BGI) • Luminosity scans typical values of at LHC: 0.2 – 1 mm
Current limitations of LHC emittance monitors • Wire Scanners (WS): cannot be used beyond a given intensity limit (depends on energy), wires break, movable device, not a continuous measurement, saturation effects (need to adjust PMT HV vs beam intensity). • Synchrotron light monitors (BSRT): absolute calibration is difficult, the source point moves during ramp, too small signal for ions at low energy, ... • Beam-gas ionization monitors (BGI): broadening of the profile due to too weak guiding field, distortion, difficult calibration, ... • Luminosity scans: must move the beams at the experiments, measures a convolution of two beam emittances, takes times, ...
SeePlamen’s talk atrecent Workshop 9th DITANET Topical Workshop on Non-Invasive Beam Size Measurement for High Brightness Proton and Heavy Ion Accelerators, 16 April 2013 Can do also: full transverse profiles (not just RMS), ghost charge, relative bunch charges Non intrusive! No beamsmoved !
Proposal to use BGV at LHC • Phase 1: BGV demonstrator at LHC ring2 (LS1) • make a sequence of measurements, bunch-by-bunch, during the ramp • Phase 2: build a full-blown BGV for each LHC ring (LS2) • Later ... other accelerators ? • «collaboration» required: BE-BI, TE-VSC, PH, EPFL, Aachen Proposalpresentedat LMC 164 (27/3/2013):... «Steve Myers summarized that in principle the LMC agreed that this was a very important, useful piece of equipment. Frederick Bordryinvited PlamenHopchev and Rhodri Jones to come to the LSC meeting on Friday morning to check the full impact .» Alsopresented to and supported by HL-LHC committee.
Passedmilestones • 2013-03-18: HL-LHC Technical Committee • The demonstrator BGV project is approved and funded by HL-LHC • 2013-03-27: Lhc Machine Committee Slides • LMC approves continued development of the monitor • LMC states that amount of work done in LS1 will depend on impact on the schedule & other Groups • 2013-05-17: Long Shutdown Committee Slides • Presented the project and the space-reservation request • Request accepted • 2013-06-04: LHCbTechnicalBoard • LHCbaccepts to providespareequipment if available in sufficientquantities More milestones to bedefined... ( =>Bernd’s talk)
Whois BGV ? (in randomorderapartfromPhDstudentsdedicated to BGV) CERN/BE: Maria Kuhn Quentin Veyrat PlamenHopchev Enrico Bravin Bernd Dehning Ray Veness Nicolas Chritin Giuseppe Bregliozzi (TE) Benoit Salvant ... CERN/PH: Mariana Rihl RosenMatev ColinBarschel MFL Richard Jacobsson JaapPanman ... LPHE: Guido Haefeli Mark Tobin Frederic Blanc Raymond Frei Aurelio Bay Tatsuya Nakada Bernard Florian ... Aachen: Thomas Kirn Stefan Schael ... we are just starting to befurtherdeveloped/defined/formalized...
Demonstrator: gastarget sketch gas injection and accumulation WF suppression long (small diameter) pipes act as flow restrictions detector beam detector pumping pumping this must be transparent! (thin) to beoptimized: ratio of useful/total gasintegral p more realistic pressure profile ideal pressure profile z Reminder: contrary to VELO/LHCb, here gas injection must be continuous (with beam)... Consider impact on machine!
Demonstrator: gross concept Aim: about 200 good events per 1e11p bunch in a few minutes => need about 1Hz good events per nominal bunch Evt size = ~ 17 bits/clus * 10 clus/plane/Evt * 8 planes = 0.2 kB/Evt 0.2 kB/evt * 1 kEvt/s = 0.2 MB/s 0.2 MB/s * 107 s = 2 TB/year mayneed to think about nano events... High Level Trigger: 1 MHz input rate thlt = avge time to take HLT decision Ncpu = nr of CPU coresavailable in HLT = 100 Weneed to achievethlt < Ncpu / RL0 = 0.1 ms • Rawgas rates: 50Hz/1011p • per meter of 6.4x10-8 mbar Ne • Hence: • - full beam (3x1014p) • - full gaslength (5m) • 0.75MHz raw rate • Shouldstay <1MHz!! • simple activity trigger readoutnetwork CPU farm readout boards storage Readout supervisor LHC clock data (max 1MHz) trigger Shielded area LHC tunnel FE electronics gastarget tracking detectors timing/trig detectors Use SciFi/SiPM ! Use VELO-likereadout (Beetle to Tell1).
detector DAQ / CTRL (VELO like) Zero suppression VME 9U TELL1 copper, analog BASELINE x8 ADC 60m ADC Gbit nw to CPUs ADC ADC LV x8 READOUT SUPERVISOR VME 9U CTRL could be the same crate FE board LHC clock drv drv drv drv LVreg TTC VME 6U max 6 FE boards TTCex L0 trig ECS control PC SPECS slave 25m (L>25m must be tested) SPECS MASTER 4 Beetles per drv x2 1m L0 detector signals patch voltage supply ctrl/trig data HV 1 per SiPM ? Beetle Beetle Beetle Beetle SiPM SiPM SiPM SiPM SciFimattress SciFimattress SciFimattress SciFimattress Beetle Beetle Beetle Beetle SiPM SiPM SiPM SiPM x8 Beetle Beetle Beetle Beetle SiPM SiPM SiPM SiPM Beetle Beetle Beetle Beetle SiPM SiPM SiPM SiPM designed for ~kGy krad «no radiation»
detector side of readoutchain • exampleherefrom VELO Zap test (PS booster 2009) • Reminder: 1 drvcard = 1 data cable = 4 Beetles drv here only 2 out of 4 driver cards Repeater (FE) board LVreg ECS mezzanine Analog data cables here only 2 out of 4 Control/trigcable here bricolaged from two CAT6 cables Temperaturescable LV and HV
Ctrl & Readout system • will more or less look likethis: (here a picturefrom the VELO assemblylab) For BGV, weneed: 8 equiped TELL1s 1 crate (Tell1 9U) 2 CTRL boards 8 equiped RPT boards 1 ODIN + Cu2Opt Copper2Optical ODIN temperaturesboard CONTROL board TELL1s Analogcables
Location: ring 2 , left of IP4 Detector A beam 2 ~10m C Rack B Rack D ? power outlets E ? IP connections • Approximate distances: A-B = 20m, B-C = 25m • Location B for DAQ/CTRL wouldbebetter: shortercables, cheaper (maybewe have mostcablesalready!) and no uncertainty about CTRL boardcablelengths... Can wemerge C into B ?? In fact, anywhere in the pink area wouldbe OK (<25m) • Location D: power outlet ? E: network connections ?
Tunnel space (about 222m left of IP4) ring2 ring1 IP4
Global time line 2014 2015 2013 • Anythingthatcannotbeinstalled in a short technical stop, shouldbeinstalled in LS1 ! More in Bernd’s talk Design studies / specs Production/testing Installation Commissioning Sep: BGV ECR (technical design) Jun: end of (heavy) work in tunnel Feb: Beam ?
Work packages and coordination Vacuum system BE / Bernd Dehning Control & Monitoring BE / PlamenHopchev ? • Today: agree on WP & Coordinators • Next step: define subtasks, names of responsibles, and milestones SciFi Aachen / Thomas ? Btl PCB EPFL / Guido Physics software BE / PlamenHopchev Detector modules EPFL / Aurelio Bay ? Global Coordination BE / Bernd Dehning & PlamenHopchev Module design EPFL / Guido ? ... Cooling R&D/design EPFL / Aurelio Bay ? Trig/DAQ PH / MFL Mechanical support BE / Ray Veness ? ... cooling /services ?