diff --git a/Tracker/MagneticField/FASERBField_xyz.txt b/Tracker/MagneticField/FASERBField_xyz.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d6cec352653ad301705f06cf3684dd53e46a60fc
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diff --git a/Tracker/MagneticField/README.txt b/Tracker/MagneticField/README.txt
new file mode 100644
index 0000000000000000000000000000000000000000..98085e11e27f1fb1b593afff4779c6fb0a32f2be
--- /dev/null
+++ b/Tracker/MagneticField/README.txt
@@ -0,0 +1,16 @@
+brief info for FASERBField_xyz.txt
+file format : txt
+coordinate system : xyz
+Dimensions : x[-100.,100.],y[-100.,100.],z[0.,4400.]
+Length units : mm
+bField unit : T
+nBins : [41,41,880]
+first quadrant/octant : false
+
+The file FASERBField_xyz.txt was created on 21.08.2019. It contains full magnetic field map (all octants) of the magnetic flux density in cartesian coordinates for different positions, spanning from -0.1m to 0.1m in x/y and from 0m to 4.4m in z. The first row gives the x position, the second the y position, the third the z position, the fourth the magnetic flux density in x (Bx), the fith the magnetic flux density in y (By), the sixth row is the magnetic flux density in z (Bz), and the last the total magnitude of the flux density. The positions are given in 0.05m steps and have 41 bins in x/y and 880 bins in z. The length unit is millimeter (mm) and the unit of the magnetic flux density is Tesla(T).
+
+The file FASERBField_xyz.root was created on 21.08.2019 from the the file FASERBField_xyz.txt using the script 'calypso/Tracker/MagneticField/translateBFieldMap.cpp' with the following command:
+
+translateBFieldMap("FASERBField_xyz.txt","FASERBField_xyz.root","bField",false,1.,1.)
+
+It contains the full magnetic field map (all octants) of the magnetic flux density in cartesian coordinates for different positions, spanning from -0.1m to 0.1m in x/y and from 0m to 4.4m in z. The positions are given in 0.05m steps and have 41 bins in r/x/y 880 bins in z. The length unit is millimeter (mm) and the unit of the magnetic flux density is Tesla(T). The file contains a tree ‘bField’ which has the following branches describing the coordinates of the positions and the different components of the magnetic flux density: ‘x’,’y’,’z’,’Bx’,’By’,’Bz’.
\ No newline at end of file
diff --git a/Tracker/MagneticField/translateBFieldMap.cpp b/Tracker/MagneticField/translateBFieldMap.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e76dcfbb2f67b231ffdde4736a30db329a05768e
--- /dev/null
+++ b/Tracker/MagneticField/translateBFieldMap.cpp
@@ -0,0 +1,129 @@
+/*
+ * translateBFieldMap.cpp
+ *
+ * Created on: 29 Jan 2018
+ * Author: jhrdinka
+ */
+
+/// This root file translates a txt/csv bField map into a root ttree
+
+/// @param inFile The path to the txt/csv input file
+/// @param outFile The name of the output root file
+/// @param outTreeName The name of the tree of the output file
+/// @param rz Set this flag to true if the magnetic field map is given in rz
+/// cooridantes instead of cartesian coordinates
+/// @param bScalor A scalor for the magnetic field to be applied
+/// @param lScalor A scalor to the length to be applied
+void
+translateBFieldMap(std::string inFile,
+ std::string outFile,
+ std::string outTreeName,
+ bool rz,
+ double bScalor = 1.,
+ double lScalor = 1.)
+{
+
+ std::cout << "Registering new ROOT output File : " << outFile << std::endl;
+
+ TFile* outputFile = TFile::Open(outFile.c_str(), "RECREATE");
+ if (!outputFile) std::cout << "Could not open '" << outFile << std::endl;
+ TTree* outputTree = new TTree(outTreeName.c_str(), outTreeName.c_str());
+ if (!outputTree) std::cout << "Could not allocate tree" << std::endl;
+
+ if (rz) {
+
+ /// [1] Read in field map file
+ std::cout << "Opening new txt/csv input File : " << outFile << std::endl;
+ std::ifstream map_file(inFile.c_str(), std::ios::in);
+ // [1] Read in file and fill values
+ std::string line;
+ double rpos = 0., zpos = 0.;
+ double br = 0., bz = 0.;
+
+ // The position value in r
+ double r;
+ outputTree->Branch("r", &r);
+
+ double z;
+ outputTree->Branch("z", &z);
+ // The BField value in r
+ double Br;
+ outputTree->Branch("Br", &Br);
+
+ double Bz;
+ outputTree->Branch("Bz", &Bz);
+
+ while (std::getline(map_file, line)) {
+ if (line.empty() || line[0] == '%' || line[0] == '#'
+ || line.find_first_not_of(' ') == std::string::npos)
+ continue;
+
+ std::istringstream tmp(line);
+ tmp >> rpos >> zpos >> br >> bz;
+
+ z = zpos * lScalor;
+ r = rpos * lScalor;
+ Br = br * bScalor;
+ Bz = bz * bScalor;
+ outputTree->Fill();
+ }
+
+ outputFile->cd();
+
+ outputFile->cd();
+ outputTree->Write();
+
+ map_file.close();
+
+ } else {
+ /// [1] Read in field map file
+ std::cout << "Opening new txt/csv input File : " << outFile << std::endl;
+ std::ifstream map_file(inFile.c_str(), std::ios::in);
+
+ // The position values in xy
+ double x;
+ outputTree->Branch("x", &x);
+
+ double y;
+ outputTree->Branch("y", &y);
+
+ double z;
+ outputTree->Branch("z", &z);
+
+ // The BField values in xy
+ double Bx;
+ outputTree->Branch("Bx", &Bx);
+
+ double By;
+ outputTree->Branch("By", &By);
+
+ double Bz;
+ outputTree->Branch("Bz", &Bz);
+
+ std::string line;
+ double xpos = 0., ypos = 0., zpos = 0.;
+ double bx = 0., by = 0., bz = 0.;
+ while (std::getline(map_file, line)) {
+ if (line.empty() || line[0] == '%' || line[0] == '#'
+ || line.find_first_not_of(' ') == std::string::npos)
+ continue;
+
+ std::istringstream tmp(line);
+ tmp >> xpos >> ypos >> zpos >> bx >> by >> bz;
+
+ x = xpos * lScalor;
+ y = ypos * lScalor;
+ z = zpos * lScalor;
+ Bx = bx * bScalor;
+ By = by * bScalor;
+ Bz = bz * bScalor;
+
+ outputTree->Fill();
+ }
+
+ outputFile->cd();
+ outputTree->Write();
+
+ map_file.close();
+ }
+}
diff --git a/Tracker/MagneticField/visualisation/README.txt b/Tracker/MagneticField/visualisation/README.txt
new file mode 100644
index 0000000000000000000000000000000000000000..3da4e59efb8748dd1559cc8aa9525f9816071048
--- /dev/null
+++ b/Tracker/MagneticField/visualisation/README.txt
@@ -0,0 +1,9 @@
+This repository contains plots and pictures of the FASER magnetic field.
+
+The file 'FASERBField_xyz_Map.root' was created from 'FASERBField_xyz.root' using the root script 'printBField' :
+
+printBField("../FASERBField_xyz.root","bField","FASERBField_xyz_Map.root",-0.1,0.1,0.,4.4,41,880)
+
+It contains histograms of the FASER magnetic field map in xy,zx and zy.
+
+The files 'xy.png', 'xz.png' and 'yz.png’ are screen shots of the above histograms.
\ No newline at end of file
diff --git a/Tracker/MagneticField/visualisation/printBField.cpp b/Tracker/MagneticField/visualisation/printBField.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..bf3be6498b060a559f62b3fbb59a2a2f1ab7cea3
--- /dev/null
+++ b/Tracker/MagneticField/visualisation/printBField.cpp
@@ -0,0 +1,144 @@
+// This file is part of the Acts project.
+//
+// Copyright (C) 2017 Acts project team
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <TTreeReader.h>
+#include <TTreeReaderValue.h>
+#include "TFile.h"
+#include "TH1F.h"
+#include "TH2F.h"
+#include "TProfile.h"
+#include "TROOT.h"
+#include "TTree.h"
+
+// This script prints the histogram of a magnetic field map.
+// To be used with the Output of the RootInterpolatedBFieldWriter.
+
+/// to print out the FCC field map please use
+/// @code
+/// printBField("FCChhBField.root","bField","printBField_FCC.root",-20.,20.,-30.,30.,400.)
+/// @endcode
+/// ro print out the ATLAS BField map pleas use
+/// @code
+/// printBField("ATLASBField.root","bField","printBField_ATLAS.root",-10.,10.,-15.,15.,200.)
+/// @endcode
+
+/// @param inFile The root input file containing the magnetic field values and
+/// positions either in cylinder (Branch names: 'r','z','Br','Bz') or cartesian
+/// coordinates (Branch names: 'x','y','z','Bx','By','Bz')
+/// @param the name of the tree containing the branches
+/// @param rMin The minimum value of the position in either r (for cylinder
+/// coordinates) or x/y (for cartesian coordinates) to be printed in [m]
+/// @param rMin The minimum value of the position in either r (for cylinder
+/// coordinates) or x/y (for cartesian coordinates) to be printed in [m]
+/// @param rMin The maximum value of the position in either r (for cylinder
+/// coordinates) or x/y (for cartesian coordinates) to be printed in [m]
+/// @param rMin The minimum value of the position in z in [m]
+/// @param rMin The maximum value of the position in z in [m]
+/// @param nBins Number of bins which should be used for the histogram (on all
+/// axes)
+/// @note This script just writes out the values which are read in from the
+/// given input file. It does no interpolation inbetween the values. This means,
+/// in case the binning is chosen too high, empty bins will appear.
+void
+printBField(std::string inFile,
+ std::string treeName,
+ std::string outFile,
+ float rmin,
+ float rmax,
+ float zmin,
+ float zmax,
+ int nBins,
+ int nBinsZ)
+{
+ const Int_t NRGBs = 5;
+ const Int_t NCont = 255;
+ Double_t stops[NRGBs] = {0.00, 0.34, 0.61, 0.84, 1.00};
+ Double_t red[NRGBs] = {0.00, 0.00, 0.87, 1.00, 0.51};
+ Double_t green[NRGBs] = {0.00, 0.81, 1.00, 0.20, 0.00};
+ Double_t blue[NRGBs] = {0.51, 1.00, 0.12, 0.00, 0.00};
+ TColor::CreateGradientColorTable(NRGBs, stops, red, green, blue, NCont);
+ gStyle->SetNumberContours(NCont);
+ gStyle->SetOptStat(0);
+
+ std::cout << "Opening file: " << inFile << std::endl;
+ TFile inputFile(inFile.c_str());
+ std::cout << "Reading tree: " << treeName << std::endl;
+ TTree* tree = (TTree*)inputFile.Get(treeName.c_str());
+
+ TTreeReader reader(treeName.c_str(), &inputFile);
+
+ double x = 0., y = 0., z = 0., r = 0.;
+ double Bx = 0., By = 0., Bz = 0., Br = 0.;
+
+ // find out if file is given in cylinder coordinates or cartesian corrdinates
+ bool cylinderCoordinates = false;
+ if (tree->FindBranch("r")) {
+ cylinderCoordinates = true;
+ tree->SetBranchAddress("r", &r);
+ tree->SetBranchAddress("Br", &Br);
+ } else {
+ tree->SetBranchAddress("x", &x);
+ tree->SetBranchAddress("y", &y);
+ tree->SetBranchAddress("Bx", &Bx);
+ tree->SetBranchAddress("By", &By);
+ }
+ // should be given for sure
+ tree->SetBranchAddress("z", &z);
+ tree->SetBranchAddress("Bz", &Bz);
+
+ Int_t entries = tree->GetEntries();
+ std::cout << "Creating new output file: " << outFile
+ << " and writing out histograms. " << std::endl;
+ TFile outputFile(outFile.c_str(), "recreate");
+
+ TProfile2D* bField_rz = new TProfile2D(
+ "BField_rz", "Magnetic Field", nBinsZ, zmin, zmax, nBins * 0.5, 0., rmax);
+ bField_rz->GetXaxis()->SetTitle("z [m]");
+ bField_rz->GetYaxis()->SetTitle("r [m]");
+ TProfile2D* bField_xy = new TProfile2D(
+ "BField_xy", "Magnetic Field", nBins, rmin, rmax, nBins, rmin, rmax);
+ bField_xy->GetXaxis()->SetTitle("x [m]");
+ bField_xy->GetYaxis()->SetTitle("y [m]");
+ TProfile2D* bField_yz = new TProfile2D(
+ "BField_yz", "Magnetic Field", nBinsZ, zmin, zmax, nBins, rmin, rmax);
+ bField_yz->GetXaxis()->SetTitle("z [m]");
+ bField_yz->GetYaxis()->SetTitle("y [m]");
+ TProfile2D* bField_xz = new TProfile2D(
+ "BField_xz", "Magnetic Field", nBinsZ, zmin, zmax, nBins, rmin, rmax);
+ bField_xz->GetXaxis()->SetTitle("z [m]");
+ bField_xz->GetYaxis()->SetTitle("x [m]");
+
+ for (int i = 0; i < entries; i++) {
+ tree->GetEvent(i);
+ if (cylinderCoordinates) {
+ float bFieldValue = sqrt(Br * Br + Bz * Bz);
+ bField_rz->Fill(z / 1000., r / 1000., bFieldValue);
+ } else {
+ float bFieldValue = sqrt(Bx * Bx + By * By + Bz * Bz);
+
+ bField_xy->Fill(x / 1000., y / 1000., bFieldValue);
+ bField_yz->Fill(z / 1000., y / 1000., bFieldValue);
+ bField_xz->Fill(z / 1000., x / 1000., bFieldValue);
+ }
+ }
+ inputFile.Close();
+
+ if (!cylinderCoordinates) {
+ bField_xy->Write();
+ bField_yz->Write();
+ bField_xz->Write();
+ } else
+ bField_rz->Write();
+
+ delete bField_rz;
+ delete bField_xy;
+ delete bField_yz;
+ delete bField_xz;
+
+ outputFile.Close();
+}
diff --git a/Tracker/MagneticField/visualisation/xy.png b/Tracker/MagneticField/visualisation/xy.png
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diff --git a/Tracker/MagneticField/visualisation/xz.png b/Tracker/MagneticField/visualisation/xz.png
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diff --git a/Tracker/MagneticField/visualisation/yz.png b/Tracker/MagneticField/visualisation/yz.png
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