aida-slide-2015-037 aida - cdsweb.cern.ch · aida-slide-2015-037 aida advanced european...

AIDA-SLIDE-2015-037

AIDAAdvanced European Infrastructures for Detectors at Accelerators

Presentation

FCAL software status and performancestudies

Rosca, A (DESY)

23 May 2012

The research leading to these results has received funding from the European Commissionunder 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<http://cern.ch/aida> or on the CERN Document Server at the following URL:

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

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.


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: 0.172RMS: 0.274RMS: 0.041


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

Visi

ble

ener

gy fo

r 250

GeV

ele

ctro

ns [G

eV]

2

2.2

2.4

2.6

2.8

3

Gap cut: 4.8mm, 24.08% in gap Gap hitSensor 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 −CD

"

#$

%

&'2"

#$$

%

&''

−E ⋅e−F⋅x2

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


Energy Resolu2on

7

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


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.


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:


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


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


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 the latest beam parameter sesngs.


Ring Energy dep

osi2on

, GeV

BeamCal Performance

13

Calibra2on curve EE%36

=σ Energy resolu2on


Reconstruc2on Efficiency

14

0

20

40

60

80

100

120

24 32 40 48 56 64 72 80 88 96 104 112 120 128 136

Efficien

cy, %

Radius, mm

Cluster Reconstruc9on Efficiency for TDR 1 TeV Beam Parameters 500 GeV 100 GeV 150 GeV 200 GeV 250 GeV

Single electrons, with energies 50 GeV, 100 GeV, 150 GeV, 200 GeV and 250 GeV,

φ ∈ [0, 2π ], θ ∈ [0.0067, 0.038] rad


Summary •  Realis2c Mokka simula2on models, in agreement with

mechanical design.

•  Tested and debugged Mokka drivers, ready for DBD produc2on.

•  Reconstruc2on code is part of the standard reconstruc2on chain.

•  Tile gap effect in LumiCal understood and corrected for.

•  Very large incoherent pair backgrounds for 1TeV TDR beam parameters, its impact needs to be beUer understood.


aida-slide-2015-037 aida - cdsweb.cern.ch · aida-slide-2015-037 aida advanced european...

Documents