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Hands-on

Rotate the Tube volume so that the tube symmetry axis is parallel with y-axis of the world reference frame.
- Hint: See slide #20 in the geometry presentation from Monday.
Complete the EDMagneticField and EDDetectorConstructionclasses to define a magnetic field with B=1.0*tesla in the y-direction and which is limited to the Tube volume.
- Update the EDMagneticField class first; follow the comments in the code
- Hint: See the slide with an example of a local magnetic field and adapt this code sample to our case
After including the magnetic field, charged particles do not reach the second arm of the detector. Rotate the second arm by 30 degree around Y axis and check that particles are again detected in the second arm.
- Hint: You can use the rotateY(G4double angle) function defined for G4ThreeVector to apply the rotation to the second arm position to place it where needed:
```
G4ThreeVector secondArmPosition(0, 0, zpos);
secondArmPosition.rotateY(-armAngle);
```
Add the changes necessary for multi-threading and activate the multi-threading mode by setting G4RunManagerType::Default in main().
When the magnetic field is implemented you can activate its visualization with the UI command: /vis/scene/add/magneticField in vis.mac.

Re-implement calorimeter layers with use of G4PVReplica.
Then add an additional level of 3 divisions in y axis.
- Note: After adding the divisions in y axis (cells), the sensitive detector EDEmCalorimeterSD has to be associated with the new replica logical volume (cellLV). Also the code used to get the calorimeter layer number has to be adapted for this change in geometry.