SiIT simulations

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  • Gauss v42r3 with modified GenConf, adapted to include SiIT
  • Boole v25r1 with modified hole (with size of SiIT) in the centre of OT


  • SiIT geometry included in LHCb upgrade XML at the place of current IT /afs/
    • 2 stations at positions of current IT1&3
    • 5 Si planes per station, 2623x649x0.444 mm, with a 200x200 mm beampipe hole in the middle
    • each plane has 2 carbon boxes for tab + front end electronics + support above and under, 2623x150x0.5 mm
    • each plane has cables (Cu) above and under, 2623x2025x0.025 mm
    • the 5 planes are embedded in a carbon box, 2800x950x60 mm
    • surrounding the 5 Si + FE planes is a carbon box 2800x950x60 mm, 0.3 mm thick, with a cylinder cut ( radius 98.5 mm, thickness 0.3 mm) out for the beam pipe.
    • 2 vertical Carbon support columns (height 5 m, width & thickness like existing IT support columns)
    • detector elements defined for all volumes
      Panoramix screenshot (SiIT-panoramix-screenshot.jpg) Geant 4 OpenGL visualiser screenshot ( SiITgeant4.png)
      SiIT-panoramix-screenshot.jpg SiITgeant4.png

Checks of the geometry

Radiation length vs z ( X/X0 Si = 0.444/122.95 = 0.0036) Eta vs radiation length
radlengthvsz.png etavsradlength.png
X-ray SiIT station 1 r vs z of electrons (after geant 4)
siit1radlength-lego.png siitelectronzvsr.png

Simulation configurations with corresponding datasets nu=2.9, L=1x10**33

  1. OT occupancies with current LHCb: /afs/
    • 10 k events under /castor/*.sim and *.digi
    • histograms in /afs/
    • DDDBtag = "MC2011-20120727", CondDBtag = "MC2011-20120727-vc-md100"
    • Gauss v42r3, Boole v25r1 and DB from release area
  2. OT occupancies with current LHCb but without IT: /afs/
    • 10 k events under /castor/*.sim and *.digi
    • histograms in /afs/
    • DDDBtag = "MC2011-20120727", CondDBtag = "MC2011-20120727-vc-md100"
    • Gauss v42r3, Boole v25r1 and DB from release area
    • 1 divided by 2 otoccitoffoveriton-gaussv42r3.png (occ-ITOff-Gaussv42r3-md100-nu2.9-10kev.root divided by occ-ITon-Gaussv42r3-md100-nu2.9-10kev.root); otoccitoffoveriton-so-gaussv42r3.png (with spillover):
      otoccitoffoveriton-gaussv42r3.png otoccitoffoveriton-so-gaussv42r3.png
  3. OT occupancies with current LHCb, without IT, but with upgrade beam pipe
    • 10 k events under /castor/*.sim and *.digi
    • DDDBtag = "dddb-20120608" , CondDBtag = "sim-20120608-vc-md100", LocalTags["DDDB"] = ["pipe-20120724"] and CondDB().Upgrade=True
    • Gauss v42r3, Boole v25r1 and DB from release area
    • 2 divided by 3, otoccitoffupgradeovercurrentbp-gaussv42r3.png (occ-ITOff-Gaussv42r3-UpBp--nu2.9-10kev.root divided by occ-ITOff-Gaussv42r3-md100-nu2.9-10kev.root), otoccitoffupgradeovercurrentbp-so--gaussv42r3.png::
      otoccitoffupgradeovercurrentbp-gaussv42r3.png otoccitoffupgradeovercurrentbp-so--gaussv42r3.png
  4. OT occupancies with current LHCb, without IT, with upgrade beam pipe and larger OT hole (size of SiIT): /afs/
    • OT hits with y > (0,0,0,0,325,325,325,325,325,325) removed (left tor ight correspond to OT modules from outside to inside). Done with a local version of Boole v25r1.
    • Use the .sim files from /castor/*.sim
    • 10k events under /castor/
    • 3 divided by 4, otoccbigovercurrentithole-gaussv42r3.png (occ-IThole-Gaussv42r3-UpBp-md100-nu2.9-10kev.root divided by occ-ITOff-Gaussv42r3-UpBp-md100-nu2.9-10kev.root), otoccbigovercurrentithole-so-gaussv42r3.png:
      otoccbigovercurrentithole-gaussv42r3.png otoccbigovercurrentithole-so-gaussv42r3.png
  5. OT occupancies with upgrade LCHb, with SiIT: /afs/
    • DDDBtag = "dddb-20121018", CondDBtag = "simcond-20121001-vc-md100", CondDB().Upgrade=True
    • DDDBConf(DbRoot = "/afs/")
    • 10 k events under /castor/*.sim
    • digitized with Boole v25r1 as under 4
      4 divided by 5: otoccbighole0versiit-gaussv42r3.png (occ-IThole-Gaussv42r3-UpBp-md100-nu2.9-10kev.root divided by occ-SiIT-Gaussv42r3-UpBp-MC-md100-nu2.9-10kev.root) otoccbighole0versiit-so-gaussv42r3.png 4 divided by 1, occbigholeoverit-gaussv42r3.png (occ-IThole-Gaussv42r3-UpBp-md100-nu2.9-10kev.root divided by occ-ITon-Gaussv42r3-md100-nu2.9-10kev.root)
      otoccbighole0versiit-gaussv42r3.png otoccbighole0versiit-so-gaussv42r3.png otoccbigholeoverit-gaussv42r3.png
      * 5 divided by 1 otoccsiovercurrentit.png (occ-SiIT-Gaussv42r3-UpBp-MC-md100-nu2.9-10kev.root divided by occ-ITon-Gaussv42r3-md100-nu2.9-10kev.root), otoccsiitovercurrentit-so-gaussv42r3.png: :
      otoccsiitovercurrentit-gaussv42r3.png otoccsiitovercurrentit-so-gaussv42r3.png
      * OT occupancies, current IT compared to SiIT for nu=0.7, nu=2.9, nu=5.7, nu=7.2 and n=9.0:
      Station1 Station2 Station3
      otstation1-nu0.7.png otstation2-nu0.7.png otstation3-nu-0.7.png
      otstation1-nu2.9.png otstation2-nu2.9.png otstation3-nu-2.9.png
      otstation1-nu5.7.png otstation2-nu5.7.png otstation3-nu-5.7.png
      otstation1-nu7.2.png otstation2-nu7.2.png otstation3-nu-7.2.png
      otstation1-nu9.0.png otstation2-nu9.0.png otstation3-nu-9.0.png
      otstation1-so-nu110-t8-56.png otstation2-so-nu110-t8-56.png otstation3-so-nu110-t8-56.png
  6. Max OT occupancies (with current IT and SiIT) as a function of nu:
  7. OT occupancies with upgrade LHCb, OT moved infront of SiIT: /afs/
    • DDDBtag = "dddb-20121018", CondDBtag = "simcond-20121001-vc-md100", CondDB().Upgrade=True
    • DDDBConf(DbRoot = "/afs/", with z="OTZPos-33.5*cm" in T/geometry.xml) and in the
           def setOTStationPositions():
              from Configurables import Gauss, MCHitMonitor
              from GaudiKernel import SystemOfUnits
              for spill in set([""]+list(Gauss().getProp("SpilloverPaths"))):
                  MCHitMonitor("OTHitMonitor"+spill).zStations = [ 7603.0*, 8290.0*, 8980.0* ]
    • 10 k events under /castor/*.sim
    • digitized with Boole v25r1 as under 4
      6 divided by 5 otoccsiitotmovedoversiit-gaussv42r3.png (occ-OTmov-Gaussv42r3-UpBp-md100-nu2.9-10kev.root divided by occ-SiIT-Gaussv42r3-UpBp-md100-nu2.9-10kev.root) 6 divided by 1: otoccsiitotmovedovercurrentit-gaussv42r3.png (occ-OTmov-Gaussv42r3-UpBp-md100-nu2.9-10kev.root divided by occ-ITon-Gaussv42r3-md100-nu2.9-10kev.root)
      otoccsiitotmovedoversiit-gaussv42r3.png otoccsiitotmovedovercurrentit-gaussv42r3.png

OT tracking efficiencies

With current IT (all OT only tracks) With current IT, only tracks outside upgrade hole With SiIT
oteffvslumi-virtualhole-nu110-noinupot-10kev.png oteffvslumi-virtualhole-nu110-inupot-10kev.png oteffvslumi-siit-virtualhole-nu110.png

IT and SiIT occupancies

it-siit-topocc-nu07.png it-siit-topocc-nu29.png it-siit-topocc-nu57.png
it-siit-sideocc-nu07.png it-siit-sideocc-nu29.png it-siit-sideocc-nu57.png
it-siit-topocc-nu72.png it-siit-topocc-nu90.png it-siit-topocc-nu110.png
it-siit-sideocc-nu72.png it-siit-sideocc-nu90.png it-siit-sideocc-nu110.png

* IT tracking efficiency as a function of nu:
* Maximum IT & SiIT occupancies as a function of nu. Note that at nu=7.2 the max SiIT occupancy is ~2.4%. This corresponds to the IT occupancy at nu~1.4, where the IT tracking efficiency is ~96%. Thus we can expect good SiIT tracking efficiency at upgrade conditions.

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Topic revision: r27 - 2013-05-22 - EricvanHerwijnen
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