exampleComposedGeo.cpp File Reference

Example (cylindrical) drift chamber application (composed trajectory with geometric constraint). More...

#include <time.h>
#include "exampleUtilCdc.h"
#include "GblTrajectory.h"

Go to the source code of this file.

Functions
void	exampleComposedGeo ()
	Drift chamber example. More...

Detailed Description

Example (cylindrical) drift chamber application (composed trajectory with geometric constraint).

Author

Claus Kleinwort, DESY, 2023 (Claus.nosp@m..Kle.nosp@m.inwor.nosp@m.t@de.nosp@m.sy.de)

Copyright

Copyright (c) 2023 Deutsches Elektronen-Synchroton, Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details.

You should have received a copy of the GNU Library General Public License along with this program (see the file COPYING.LIB for more details); if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Definition in file exampleComposedGeo.cpp.

Function Documentation

exampleComposedGeo()

void exampleComposedGeo

(

)

Drift chamber example.

Simulate and reconstruct helical tracks in a (cylindrical) drift chamber.

Create points on initial trajectories, create COMPOSED trajectory (for two tracks from same vertex) from points, fit and write trajectory to MP-II binary file (for rigid body alignment).

Setup:

• Collider, beams in Z direction
• Constant magnetic field in Z direction
• Cylindrical drift chamber
• No multiple scattering in detectors (gas, wires, walls) (air in between ignored)
• Curvilinear system (T,U,V) as local coordinate system and (q/p, slopes, offsets) as local track parameters

Remarks

To exercise (mis)alignment different sets of layers (with different geometry) for simulation and reconstruction can be used.

Example steering file for Millepede-II (B=0, chamber alignment):

Cfiles
milleBinaryISN.dat
 
method inversion 3 0.1
chiscut 30. 6.
printcounts
! fix first layer as reference
parameter
1001  0.  -1.
1002  0.  -1.
1003  0.  -1.
1004  0.  -1.
1005  0.  -1.
1006  0.  -1.
end

Definition at line 75 of file exampleComposedGeo.cpp.

References gbl::GblPoint::addGlobals(), gbl::GblPoint::addMeasurement(), gbl::GblPoint::addScatterer(), gbl::CreateImpactPar(), gbl::CreateWireCdc(), gbl::GblTrajectory::fit(), gbl::gblMultipleScatteringError(), gbl::gblSimpleJacobian(), gbl::GblHelixPrediction::getArcLength(), gbl::GblSimpleHelix::getArcLengthR(), gbl::GblSimpleHelix::getArcLengthXY(), gbl::GblHelixPrediction::getCosIncidence(), gbl::GblHelixPrediction::getCurvilinearDirs(), gbl::GblHelixPrediction::getDirection(), gbl::GblDetectorLayer::getLayerID(), gbl::GblHelixPrediction::getMeasPred(), gbl::GblDetectorLayer::getMeasSystemDirs(), gbl::GblSimpleHelix::getPhi(), gbl::GblHelixPrediction::getPosition(), gbl::GblDetectorLayer::getPrecision(), gbl::GblDetectorLayer::getRadiationLength(), gbl::GblDetectorLayer::getResolution(), gbl::GblDetectorLayer::getRigidBodyDerGlobal(), gbl::GblDetectorLayer::intersectWithHelix(), gbl::GblTrajectory::milleOut(), gbl::GblTrajectory::printTrajectory(), gbl::unif(), and gbl::unrm().