exampleDc.cpp File Reference

Example drift chamber application. More...

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

Go to the source code of this file.

Namespaces
namespace	gbl
	Namespace for the general broken lines package.

Functions
void	exampleDc ()
	Drift chamber example. More...
GblDetectorLayer	gbl::CreateLayerDc (const std::string aName, unsigned int layer, double xPos, double yPos, double zPos, double thickness, double xzAngle, double stereoAngle, double uRes)
	Create a drift chamber layer with 1D measurement. More...

Detailed Description

Example drift chamber application.

Author

Claus Kleinwort, DESY, 2018 (Claus.nosp@m..Kle.nosp@m.inwor.nosp@m.t@de.nosp@m.sy.de)

Copyright

Copyright (c) 2018-2021 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 exampleDc.cpp.

Function Documentation

exampleDc()

void exampleDc

(

)

Drift chamber example.

Simulate and reconstruct helical tracks in a sector of (forward) drift chambers.

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

Setup:

• Beam forward (+Z) direction
• Constant magnetic field in Z direction
• Planar drift chambers with normal in XZ plane, center at Y=0, 1D measurement from (azimuthal) wires, cell size 2 cm.
• 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 chamber 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 73 of file exampleDc.cpp.

References gbl::GblPoint::addGlobals(), gbl::GblPoint::addMeasurement(), gbl::GblPoint::addScatterer(), gbl::CreateLayerDc(), gbl::GblTrajectory::fit(), gbl::gblMultipleScatteringError(), gbl::gblSimpleJacobian(), gbl::GblHelixPrediction::getArcLength(), gbl::GblHelixPrediction::getCosIncidence(), gbl::GblHelixPrediction::getCurvilinearDirs(), gbl::GblHelixPrediction::getDirection(), gbl::GblDetectorLayer::getLayerID(), gbl::GblHelixPrediction::getMeasPred(), gbl::GblDetectorLayer::getMeasSystemDirs(), gbl::GblHelixPrediction::getPosition(), gbl::GblDetectorLayer::getPrecision(), gbl::GblDetectorLayer::getRadiationLength(), gbl::GblDetectorLayer::getRigidBodyDerGlobal(), gbl::GblDetectorLayer::intersectWithHelix(), gbl::GblTrajectory::milleOut(), gbl::GblSimpleHelix::moveToXY(), gbl::unif(), and gbl::unrm().