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AIDA-SLIDE-2015-037 AIDA - · PDF file AIDA-SLIDE-2015-037 AIDA Advanced European Infrastructures for Detectors at Accelerators Presentation FCAL software status and performance studies

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  • AIDA-SLIDE-2015-037

    AIDA Advanced European Infrastructures for Detectors at Accelerators

    Presentation

    FCAL software status and performance studies

    Rosca, A (DESY)

    23 May 2012

    The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project AIDA, grant agreement no. 262025.

    This work is part of AIDA Work Package 9: Advanced infrastructures for detector R&D.

    The electronic version of this AIDA Publication is available via the AIDA web site or on the CERN Document Server at the following URL:

    AIDA-SLIDE-2015-037

    http://cern.ch/aida http://cds.cern.ch/search?p=AIDA-SLIDE-2015-037

  • Forward  Region:  Simula2on  and   Performance  Studies      

    Aura  Rosca  (DESY)   ILD  Mee2ng,  Kyushu  University,  Fukuoka,  Japan  23  -­‐  25    May  2012  

  • Introduc2on  

    2  

    •  LumiCal  goals:   – High  precision  in  ΔL/L  

    •  Bhabha  scaUering   •  10-­‐3  (√s  =  500  GeV)   •  10-­‐4  (GIGA-­‐Z)  

    •  BeamCal  goals:   –  Fast  luminosity   es2ma2on  (using   beamstrahlung)  

    – Assist  beam  tuning   – Assure  good  hermi2city  

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • LumiCal  Geometry  

    •  Mechanical  design  for  LumiCal   exists;  high  level  of  realism.  

    •  LumiCal  structure:   –  Type                                                              Si-­‐W   –  #  layers                                                          30   –  Absorber  Δz                                        1X0         –  Si  Δz                                                        300  µm                                   –  Layer  offset                                        3.75o   –  Inner  radius                                  80  mm                         –  Outer  radius                        195.2  mm   –  Distance  from  IP                      2.5  m  

    3   5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • LumiCal  Geometry  

    4  

    •  Realis2c  soiware  model  in  agreement  with  the  mechanical  design   •  Sensi2ve  detector  very  detailed:  

    -  2le  gaps,  pad  metaliza2on,  support  structure,  cooling,  electronics.    

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Implementa2on  of  Gaps  

    5  

    •  Gaps  between  sensors  implemented  in  the  geometry.     •  Strong  gap  effects,  need  to  be  simulated  and  corrected.   -  reject  energy  deposi2ons  on  the  2le  gap   -  fit  the  energy  deposi2ons  in  gaps  

    Visible energy [GeV] 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

    1

    10

    210

    Visible energy [GeV] 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

    1

    10

    210

    Energy deposited by 250 GeV e-

    Reference design

    No rotation

    No gaps

    RMS: 0.172 RMS: 0.274 RMS: 0.041

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Azimuthal angle [deg] -150 -100 -50 0 50 100 150

    Vi si

    bl e

    en er

    gy fo

    r 2 50

    G eV

    e le

    ct ro

    ns [G

    eV ]

    2

    2.2

    2.4

    2.6

    2.8

    3

    Gap cut: 4.8mm, 24.08% in gap Gap hit Sensor hit

    LumiCal  Performance  

    6  

    Energy  deposi2on  from  250  GeV  e-­‐   (in  the  gaps  shown  in  red)  

    Fit  with  Lorentzian  +  Gaussian  

    E(x) = A− B

    1+ x −C D

    "

    # $

    %

    & ' 2"

    # $$

    %

    & ''

    −E ⋅e−F⋅x 2

    •  Detailed  studies  with  single  electrons,   documented  in:    J.  Aguilar  et  al.,Physics   Procedia  00  (2012)  1-­‐8  

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Energy  Resolu2on  

    7  

    Stochas2c  term:  21%  -­‐>  20  %  (fit)   Constant  term:          6%  -­‐>      1  %  (fit)  

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

    Comparison  of  Different  Methods  

  • BeamCal  Geometry   •  Realis2c  simula2on  exists  in  Mokka.   •  Model  derived  from  the  mechanical  design.   •  BeamCal  geometry  described  in:      Mokka/source/Geometry/Tesla/src/BeamCal01.cc  

    –  Cylindrical  geometry     – Graphite  shield,  100  mm  thick   –  30  W  layers,  3.5  mm  thick   –  30  diamond  sensi2ve  layers   –  Cells  ~8  x  8  mm2  

    –  Two  holes  for  passing  the     tubes,  beamcal  centered     around  the  outgoing  pipe.  

    8  5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Layer  Structure    

     

       

    Kapton Gold

    Tungsten Air gap

    Diamond

    x  

    z  

    Unit   14  mrad  

    Graphite  shield   thickness  

    mm   100  

    Absorber  layer   mm   3.5  

    Sensor  layer   mm   0.3                          1X0   Readout   plane/air  gap  

    mm   0.2  

    Total  X0   30  

    9  

    Current  implementa2on  of  the  detector  layers:  

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • BeamCal  Reconstruc2on   •  Clustering/Reconstruc2on  is  done  in                                         MarlinReco/Clustering/BCalReco/src/Reconstruc2on.cc  ,  BCalReco.cc  

    •  Part  of  the  standard  reconstruc2on  chain  for  the   DBD.  

     

    •  Operates  in  the  presence  of  beam  background   •  BCalReco.cc  is  a  Marlin  processor  that  calls  the   reconstruc2on  code,  aier  a  simula2on  of  the  effect     of  backgrounds.   – Needs  the  background  deposi2ons  in  all  cells,  as  an  external   file:  bg_aver_LDC_3.5T_14mrad_An2DID_NominalBeamParam.root    

    – Must  be  renewed  for  each  set  of  beam  parameters   10  

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Overview  of  Reconstruc2on  Algorithm  

    11  

    Read  Background   Map  

    Smear  Energy

    Select  Pads  with   Epad  >  1  σ

    Build  Towers  

    Build  Clusters  

    Accept  Cluster   Calculate  E,  x,y,z

    Enmax

    Etowern > 90% Enmax

    Enmax

    Neighbouring towers of lower energy added to the cluster

    5/23/12   Aura  Rosca  -­‐  FCAL:Simula2on  and  Performancs  Studies  

  • Pair  Background  in  BeamCal  

    12  

    Etot  =  8042  GeV  

    0.01  

    0.1  

    1  

    10  

    100  

    1000  

    10000  

    1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17  

    Series1  

    Series2  

    Series3  

    TDR  1TeV   TDR  500  GeV   RDR  500  GeV  

    Radial  Energy  Distribu2ons  

    1  TeV  

    Longitudinal  Energy  Distribu2on  

    Total  Number  of  Hits  

    Very  large  energy  deposi2on  from  pairs   for

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