Implementation of BeamCal in Mokka

1
Implementation of BeamCal in Mokka

• Alexandra Popescu, Aura Rosca
• West University of Timisoara

FCAL Collaboration Meeting 6-7 May, Krakow, Poland
2
Overview

• BeamCal functionality and structure
• Detector construction
• Sensitive detectors
• Summary

3
BeamCal

• Compact EM calorimeter with a sandwich structure
• 30 layers of 1X0 3.5 mm absorber and 0.3 mm
  sensor
• Angular coverage 5-45 mrad
• Situated at 3450 mm from the IP

• Purposes
• Provide electron and photon identification down
  to polar angles of a few mrad
• Protect the inner part of the detector by
  reducing backscattering from inner parts
• Assisting beam diagnostics

4
Mokka implementation

• Create a local copy of the central database
• Construct the geometry of the detector
• Define the sensitive detectors

5
Geometry construction

• Drivers C code
• Databases MySQL database
• Sub-detectors a combination of drivers and
  databases

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Drivers

• A class which inherits from VSubDetectorDrivers
  class
• class BeamCal00 public VSubDetectorDriver
• The actual construction of the geometry is made
  by the ContextualConstruct invoked by the
  geometry manager
• G4bool ContextualConstruct(const
  CGAGeometryEnvironment env, G4LogicalVolume
  worldLog)
• To be available the driver has to be created
  using the INSTANTIATE macro available in
  CGADefs.h
• include "CGADefs.h"
• INSTANTIATE(BeamCal00)

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Geometry data model

• models03 database is composed of several
  tables
• detector_concept
• ingredients
• model
• model_parameters
• parameters
• scripts
• setup
• setup_parameters
• sharing
• sub_detector
• tmp_databases

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Geometry data model
model
name
description
detector_concept
model_status
sub_detector
id
name
db
driver
description
ingredients
id
model
sub_detector
build_order

sharing
driver
parameter
driver_default_value

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Database

• Create a database, using a MySQL script, with
  the relevant geometry parameters for the detector
• CREATE DATABASE beamcalX01_14
• USE beamcalX01_14
• DROP TABLE IF EXISTS beamcal
• CREATE TABLE beamcal(
• Rinner double default NULL,
• Router double default NULL,
• sPhi double default NULL,
• dPhi double default NULL,
• nWafers double default NULL,
• BPmaxR double default NULL
• )
• INSERT INTO beamcal (Rinner, Router, sPhi,
  dPhi, nWafers, BPmaxR) VALUES (20., 150., 200.,
  320., 8., 67.)

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Geometry construction
Connect the driver and the database to form a
sub-detector
sub_detector
id
name
db
driver
description

• name BeamCal
• driver BeamCal00
• database beamcalX01

Create a detector model that uses this
sub-detector
ingredients
id
model
sub_detector
build_order
model
name
description
detector_concept
model_status

• model LDC01_05Sc
• sub_detector BeamCal

Make the relevant geometry parameters known to
the driver
sharing
driver
parameter
driver_default_value

• driver BeamCal00
• parameter ILC_Main_Crossing_Angle (default
  value is 14 mrad)

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BeamCal Geometry
Tungsten
Kapton
Gold
Pair monitor
Graphite (100 mm)
Air gap
Diamond
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BeamCal Geometry

• Segmentation
• 17 ring (r)
• 8 sectors (phi)
• 140 cells/sector

8mm
Backward region
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Sensitive detector

• Hit class(es)
• - CalHit (the generic hit class for calorimeters)
  
• - TRKHit (implements a simple hit for the
  tracking devices)
• Hit collection
• Sensitive detector class
• has to inherit from the abstract class
  VSensitiveDetector
• Register the sensitive detector object using the
  RegsiterSensitiveDetector() method

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Hits
Forward region
Backward region
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Simulation studies
RM11.8 0.4 mm
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Summary

• Implemented in Mokka a realistic description of
  BeamCals geometry
• Moliere Radius 11.8 mm (preliminary result)
• LC TOOLS note in progress