/**
Factory for a configurable, generic tracker endcap.
@author: Valentin Volkl
*/
static DD4hep::Geometry::Ref_t createGenericTrackerEndcap(DD4hep::Geometry::LCDD& lcdd,
DD4hep::XML::Handle_t xmlElement,
DD4hep::Geometry::SensitiveDetector sensDet) {
// shorthands
DD4hep::XML::DetElement xmlDet = static_cast<DD4hep::XML::DetElement>(xmlElement);
Dimension dimensions(xmlDet.dimensions());
// get sensitive detector type from xml
DD4hep::XML::Dimension sdTyp = xmlElement.child("sensitive"); // retrieve the type
if (xmlDet.isSensitive()) {
sensDet.setType(sdTyp.typeStr()); // set for the whole detector
}
// definition of top volume
std::string detName = xmlDet.nameStr();
DetElement GenericTrackerEndcapWorld(detName, xmlDet.id());
// envelope volume with the max dimensions of tracker for visualization etc.
// contains both endcaps, in forward and in backwards direction
// the part between -z1 and z1 is subtracted from the envelope
DD4hep::Geometry::Tube posnegEnvelopeShape_add(dimensions.rmin(), dimensions.rmax(), (dimensions.z2()));
// make the negative shape slighly larger in the radial direction
// to be sure that everything is subtracted between -z1 and z1
DD4hep::Geometry::Box posnegEnvelopeShape_subtract(
dimensions.rmax() * 1.001, dimensions.rmax() * 1.001, dimensions.z1());
DD4hep::Geometry::SubtractionSolid posnegEnvelopeShape(posnegEnvelopeShape_add, posnegEnvelopeShape_subtract);
Volume posnegEnvelopeVolume(detName, posnegEnvelopeShape, lcdd.air());
posnegEnvelopeVolume.setVisAttributes(lcdd.invisible());
// envelope volume for one of the endcaps, either forward or backward
DD4hep::Geometry::Tube envelopeShape(dimensions.rmin(), dimensions.rmax(), 0.5 * (dimensions.z2() - dimensions.z1()));
Volume envelopeVolume(detName, envelopeShape, lcdd.air());
envelopeVolume.setVisAttributes(lcdd.invisible());
// loop over 'layer' nodes in xml
unsigned int layerCounter = 0;
for (DD4hep::XML::Collection_t xLayerColl(xmlElement, _U(layers)); nullptr != xLayerColl; ++xLayerColl) {
DD4hep::XML::Component xLayer = static_cast<DD4hep::XML::Component>(xLayerColl);
// create petals
unsigned int nPhi = static_cast<unsigned int>(getAttrValueWithFallback(xLayer, "nPhi", 16));
const double lModuleTwistAngle = getAttrValueWithFallback(xLayer, "module_twist_angle", 0.05 * M_PI);
double dr = xLayer.rmax() - xLayer.rmin();
double dphi = 2 * dd4hep::pi / static_cast<double>(nPhi);
double tn = tan(dphi);
Volume petalVolume(
"petal",
DD4hep::Geometry::Trapezoid(
0.5 * xLayer.rmin() * tn, 0.5 * xLayer.rmax() * tn, xLayer.thickness(), xLayer.thickness(), 0.5 * dr),
lcdd.material("Silicon"));
petalVolume.setVisAttributes(lcdd, xLayer.visStr());
petalVolume.setSensitiveDetector(sensDet);
// handle repeat attribute in xml
double layerThickness;
unsigned int numLayers;
double current_z;
// "repeat" layers equidistant between rmin and rmax
numLayers = xLayer.repeat();
layerThickness = (xLayer.z2() - xLayer.z1()) / numLayers;
// create layers.
for (unsigned int repeatIndex = 0; repeatIndex < numLayers; ++repeatIndex) {
DD4hep::Geometry::Tube layerShape(xLayer.rmin(), xLayer.rmax(), 0.5 * layerThickness);
Volume layerVolume("layer" + std::to_string(layerCounter), layerShape, lcdd.air());
layerVolume.setVisAttributes(lcdd.invisible());
++layerCounter;
// place layers not at center, but at z1 value of containing envelope
// subtract half of the envelope length
current_z = (repeatIndex + 0.5) * layerThickness + xLayer.z1() - dimensions.z1();
PlacedVolume placedLayerVolume = envelopeVolume.placeVolume(
layerVolume, DD4hep::Geometry::Position(0, 0, current_z - 0.5 * (dimensions.z2() - dimensions.z1())));
placedLayerVolume.addPhysVolID("layer", layerCounter);
double phi;
double r = xLayer.rmin();
for (unsigned int phiIndex = 0; phiIndex < nPhi; ++phiIndex) {
phi = 2 * dd4hep::pi * static_cast<double>(phiIndex) / static_cast<double>(nPhi);
// oriented along z at first
DD4hep::Geometry::Translation3D lTranslation_ringPhiPos(0, 0, r + 0.5 * dr);
DD4hep::Geometry::RotationY lRotation_ringPhiPos(phi);
DD4hep::Geometry::RotationX lRotation_orientRing(0.5 * dd4hep::pi);
// twist petals slightly so they can overlap
DD4hep::Geometry::RotationZ lRotation_twist(lModuleTwistAngle);
PlacedVolume placedPetalVolume = layerVolume.placeVolume(
petalVolume, lRotation_orientRing * lRotation_ringPhiPos * lTranslation_ringPhiPos * lRotation_twist);
placedPetalVolume.addPhysVolID("petal", phiIndex);
}
}
}
// top of the hierarchy
Volume motherVol = lcdd.pickMotherVolume(GenericTrackerEndcapWorld);
PlacedVolume placedEnvelopeVolume = motherVol.placeVolume(posnegEnvelopeVolume);
placedEnvelopeVolume.addPhysVolID("system", xmlDet.id());
// place everything twice -- forward / backward
DD4hep::Geometry::Translation3D lTranslation_posEnvelope(
0, 0, -dimensions.z1() - 0.5 * (dimensions.z2() - dimensions.z1()));
PlacedVolume placedGenericTrackerEndcap_pos = posnegEnvelopeVolume.placeVolume(
envelopeVolume, DD4hep::Geometry::Position(0, 0, dimensions.z1() + 0.5 * (dimensions.z2() - dimensions.z1())));
PlacedVolume placedGenericTrackerEndcap_neg = posnegEnvelopeVolume.placeVolume(
envelopeVolume, lTranslation_posEnvelope * DD4hep::Geometry::RotationX(dd4hep::pi));
placedGenericTrackerEndcap_pos.addPhysVolID("posneg", 0);
placedGenericTrackerEndcap_neg.addPhysVolID("posneg", 1);
GenericTrackerEndcapWorld.setPlacement(placedEnvelopeVolume);
return GenericTrackerEndcapWorld;
}
static DD4hep::Geometry::Ref_t createGenericTrackerBarrel(DD4hep::Geometry::LCDD& lcdd,
DD4hep::XML::Handle_t xmlElement,
DD4hep::Geometry::SensitiveDetector sensDet) {
// shorthands
DD4hep::XML::DetElement xmlDet = static_cast<DD4hep::XML::DetElement>(xmlElement);
Dimension dimensions(xmlDet.dimensions());
// get sensitive detector type from xml
DD4hep::XML::Dimension sdTyp = xmlElement.child("sensitive");
if (xmlDet.isSensitive()) {
// sensitive detector used for all sensitive parts of this detector
sensDet.setType(sdTyp.typeStr());
}
// definition of top volume
// has min/max dimensions of tracker for visualization etc.
std::string detectorName = xmlDet.nameStr();
DetElement topDetElement(detectorName, xmlDet.id());
DD4hep::Geometry::Tube topVolumeShape(dimensions.rmin(), dimensions.rmax(), dimensions.dz());
Volume topVolume(detectorName, topVolumeShape, lcdd.air());
topVolume.setVisAttributes(lcdd.invisible());
// counts all layers - incremented in the inner loop over repeat - tags
unsigned int layerCounter = 0;
// loop over 'layer' nodes in xml
for (DD4hep::XML::Collection_t xLayerColl(xmlElement, _U(layers)); nullptr != xLayerColl; ++xLayerColl) {
DD4hep::XML::Component xLayer = static_cast<DD4hep::XML::Component>(xLayerColl);
DD4hep::XML::Component xModuleComponents = xmlElement.child("module_components");
DD4hep::XML::Component xModule =
utils::getNodeByStrAttr(xmlElement, "module", "name", xLayer.attr<std::string>("module"));
// optional parameters
double stereo_offset = utils::getAttrValueWithFallback(xLayer, "stereo_offset", 0.0);
double module_twist_angle = utils::getAttrValueWithFallback(xLayer, "module_twist_angle", 0.1 * M_PI);
double stereo_module_overlap = utils::getAttrValueWithFallback(xLayer, "stereo_module_overlap", 0.0);
// get total thickness of module
unsigned int idxSubMod = 0;
double totalModuleComponentThickness = 0;
for (DD4hep::XML::Collection_t xCompColl(xModuleComponents, _U(module_component)); nullptr != xCompColl;
++xCompColl, ++idxSubMod) {
DD4hep::XML::Component xComp = static_cast<DD4hep::XML::Component>(xCompColl);
totalModuleComponentThickness += xComp.thickness();
}
// now that thickness is known: define module components volumes
idxSubMod = 0;
double integratedModuleComponentThickness = 0;
std::vector<Volume> moduleComponentVector;
for (DD4hep::XML::Collection_t xCompColl(xModuleComponents, _U(module_component)); nullptr != xCompColl;
++xCompColl, ++idxSubMod) {
DD4hep::XML::Component xComp = static_cast<DD4hep::XML::Component>(xCompColl);
std::string moduleComponentName = "layer" + std::to_string(layerCounter) + "_rod_module_component" +
std::to_string(idxSubMod) + "_" + xComp.materialStr();
Volume moduleComponentVolume(moduleComponentName,
DD4hep::Geometry::Box(xModule.width(), xComp.thickness(), xModule.length()),
lcdd.material(xComp.materialStr()));
moduleComponentVolume.setVisAttributes(lcdd, xComp.visStr());
if (xComp.isSensitive()) {
moduleComponentVolume.setSensitiveDetector(sensDet);
}
moduleComponentVector.push_back(moduleComponentVolume);
}
// definition of module volume (smallest independent subdetector)
// define the module whose name was given in the "layer" xml Element
Volume moduleVolume("module", DD4hep::Geometry::Box(xModule.width(), xModule.thickness(), xModule.length()),
lcdd.material("Air"));
moduleVolume.setVisAttributes(lcdd, xModule.visStr());
// definition of rod volume (longitudinal arrangement of modules)
Volume rodVolume("GenericTrackerBarrel_layer" + std::to_string(layerCounter) + "_rod",
DD4hep::Geometry::Box(xModule.width(), xModule.thickness(), xLayer.dz()),
lcdd.material("Air"));
rodVolume.setVisAttributes(lcdd.invisible());
/// @todo: allow for more than one type of module components
// analogous to module
// place module substructure in module
std::string moduleComponentName = "moduleComponent";
idxSubMod = 0;
for (DD4hep::XML::Collection_t xCompColl(xModuleComponents, _U(module_component)); nullptr != xCompColl;
++xCompColl, ++idxSubMod) {
DD4hep::XML::Component xComp = static_cast<DD4hep::XML::Component>(xCompColl);
DD4hep::Geometry::Position offset(0, -0.5 * totalModuleComponentThickness + integratedModuleComponentThickness,
0);
integratedModuleComponentThickness += xComp.thickness();
PlacedVolume placedModuleComponentVolume = moduleVolume.placeVolume(moduleComponentVector[idxSubMod], offset);
placedModuleComponentVolume.addPhysVolID("module_component", idxSubMod);
}
// handle repeat attribute in xml
// "repeat" layers equidistant between rmin and rmax
double numRepeat = xLayer.repeat();
double layerThickness = (xLayer.rmax() - xLayer.rmin()) / numRepeat;
double layer_rmin = xLayer.rmin();
unsigned int nPhi = 0;
double r = 0;
double phi = 0;
// loop over repeated layers defined by one layer tag
for (unsigned int repeatIndex = 0; repeatIndex < numRepeat; ++repeatIndex) {
++layerCounter;
// let r be the middle between two equidistant layer boundaries
r = layer_rmin + (0.5 + repeatIndex) * layerThickness;
// definition of layer volumes
DD4hep::Geometry::Tube layerShape(r - 0.5*layerThickness, r + 0.5*layerThickness, xLayer.dz());
std::string layerName = "layer" + std::to_string(layerCounter);
Volume layerVolume(layerName, layerShape, lcdd.material("Silicon"));
layerVolume.setVisAttributes(lcdd.invisible());
PlacedVolume placedLayerVolume = topVolume.placeVolume(layerVolume);
placedLayerVolume.addPhysVolID("layer", layerCounter);
// approximation of tklayout values
double phiOverlapFactor = utils::getAttrValueWithFallback(xLayer, "phi_overlap_factor", 1.15);
nPhi = static_cast<unsigned int>( phiOverlapFactor * 2 * M_PI * r / (2 * xModule.width()));
for (unsigned int phiIndex = 0; phiIndex < nPhi; ++phiIndex) {
phi = 2 * M_PI * static_cast<double>(phiIndex) / static_cast<double>(nPhi);
DD4hep::Geometry::Translation3D lTranslation(r * cos(phi), r * sin(phi), 0);
DD4hep::Geometry::RotationZ lRotation(phi + module_twist_angle + 0.5 * M_PI);
PlacedVolume placedRodVolume = layerVolume.placeVolume(rodVolume, lTranslation * lRotation);
placedRodVolume.addPhysVolID("rod", phiIndex);
}
}
// placement of modules within rods
unsigned int zRepeat = static_cast<int>(xLayer.dz() / (xModule.length() - stereo_module_overlap));
// stereo overlap
for (unsigned int zIndex = 0; zIndex < zRepeat; ++zIndex) {
stereo_offset *= -1.;
DD4hep::Geometry::Position moduleOffset(0, stereo_offset,
zIndex * 2 * (xModule.length() - stereo_module_overlap) - xLayer.dz() +
xModule.length() - stereo_module_overlap);
PlacedVolume placedModuleVolume = rodVolume.placeVolume(moduleVolume, moduleOffset);
placedModuleVolume.addPhysVolID("module", zIndex);
}
}
Volume motherVol = lcdd.pickMotherVolume(topDetElement);
PlacedVolume placedGenericTrackerBarrel = motherVol.placeVolume(topVolume);
placedGenericTrackerBarrel.addPhysVolID("system", topDetElement.id());
topDetElement.setPlacement(placedGenericTrackerBarrel);
return topDetElement;
}