Implementation of BeamCal in Mokka
Alexandra Popescu, Aura Rosca
West University of Timisoara
FCAL Collaboration Meeting
6-7 May, Krakow, Poland
7.05.2008
2
Overview
•BeamCal: functionality and structure
•Detector construction
•Sensitive detectors
•Summary
7.05.2008
3
BeamCal
Compact EM calorimeter with asandwich structure:
• 30 layers of 1X0: 3.5 mm absorber and0.3 mm sensor
• Angular coverage: ~5-45 mrad
• Situated at 3450 mm from the IP
Purposes:
• Provide electron and photon identificationdown to polar angles of a few mrad
• Protect the inner part of the detector byreducing backscattering from inner parts
• Assisting beam diagnostics
7.05.2008
4
Mokka implementation
•Create a local copy of the central database
•Construct the geometry of the detector
•Define the sensitive detectors
7.05.2008
5
Geometry construction
•Drivers: C++ code
•Databases: MySQL database
•Sub-detectors: a combination of drivers anddatabases
7.05.2008
6
Drivers
•A class which inherits from VSubDetectorDrivers class
class BeamCal00: public VSubDetectorDriver
•The actual construction of the geometry is made by theContextualConstruct invoked by the geometry manager
G4bool ContextualConstruct(const CGAGeometryEnvironment &env,G4LogicalVolume *worldLog);
•To be available the driver has to be created using the INSTANTIATEmacro available in “CGADefs.h”
#include "CGADefs.h"
INSTANTIATE(BeamCal00)
7.05.2008
7
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
7.05.2008
8
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
7.05.2008
9
Database
Create a database, using a MySQL script, with the relevant geometry parameters forthe 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.);
10
Connect the driver and the database to form a sub-detector:
Geometry construction
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: 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)
model
name
description
detector_concept
model_status
7.05.2008
11
Graphite (100 mm)
Air gap
Diamond
Kapton
Gold
Tungsten
Pair monitor
BeamCal Geometry
7.05.2008
12
Backward region
BeamCal Geometry
Segmentation:
• 17 ring (r)
• 8 sectors (phi)
• 140 cells/sector
~ 8mm
7.05.2008
13
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 theRegsiterSensitiveDetector() method
7.05.2008
14
Hits
Forward region
Backward region
7.05.2008
15
Simulation studies
RM=11.8 ±0.4 mm
7.05.2008
16
Summary
•Implemented in Mokka a realistic descriptionof BeamCal’s geometry
•Moliere Radius = 11.8 mm (preliminary result)
•LC TOOLS note in progress