// Detector plugin to support a hybrid central barrel calorimeter
// The detector consists of interlayers of Pb/ScFi (segmentation in global r, phi) and W/Si (segmentation in local x, y)
// Assembly is used as the envelope so two different detectors can be interlayered with each other
//
//
// Implementation of the Sci Fiber geometry: M. Żurek 06/19/2021
// Support interlayers between multiple detectors: C. Peng 07/09/2021
#include "DD4hep/DetFactoryHelper.h"
#include "XML/Layering.h"
#include "Math/Point2D.h"
#include "TGeoPolygon.h"
using namespace std;
using namespace dd4hep;
using namespace dd4hep::detail;
typedef ROOT::Math::XYPoint Point;
// headers for helper functions, defined in BarrelCalorimeterHybrid_geo
vector<vector<Point>> fiberPositions(double radius, double x_spacing, double z_spacing,
double x, double z, double phi, double spacing_tol = 1e-2);
std::pair<int, int> getNdivisions(double x, double z, double dx, double dz);
vector<tuple<int, Point, Point, Point, Point>> gridPoints(int div_x, int div_z, double x, double z, double phi);
void buildFibers(Detector& desc, SensitiveDetector sens, Volume &s_vol, xml_comp_t x_fiber,
std::tuple<double, double, double, double> dimensions);
// barrel ecal layers contained in an assembly
static Ref_t create_detector(Detector& desc, xml_h e, SensitiveDetector sens) {
Layering layering (e);
xml_det_t x_det = e;
Material air = desc.air();
int det_id = x_det.id();
string det_name = x_det.nameStr();
xml_comp_t x_staves = x_det.staves();
double offset = x_det.attr<double>(_Unicode(offset));
xml_comp_t x_dim = x_det.dimensions();
int nsides = x_dim.numsides();
double inner_r = x_dim.rmin();
double dphi = (2*M_PI/nsides);
double hphi = dphi/2;
DetElement sdet (det_name, det_id);
Volume motherVol = desc.pickMotherVolume(sdet);
Assembly envelope (det_name);
Transform3D tr = Translation3D(0, 0, offset) * RotationZ(hphi);
PlacedVolume env_phv = motherVol.placeVolume(envelope, tr);
sens.setType("calorimeter");
env_phv.addPhysVolID("system",det_id);
sdet.setPlacement(env_phv);
// build a single stave
DetElement stave_det("stave0", det_id);
Assembly mod_vol("stave");
// keep tracking of the total thickness
double l_pos_z = inner_r;
{ // ===== buildBarrelStave(desc, sens, module_volume) =====
// Parameters for computing the layer X dimension:
double tan_hphi = std::tan(hphi);
double l_dim_y = x_dim.z()/2.;
// Loop over the sets of layer elements in the detector.
int l_num = 1;
for(xml_coll_t li(x_det, _U(layer)); li; ++li) {
xml_comp_t x_layer = li;
int repeat = x_layer.repeat();
double l_space_between = dd4hep::getAttrOrDefault(x_layer, _Unicode(space_between), 0.);
double l_space_before = dd4hep::getAttrOrDefault(x_layer, _Unicode(space_before), 0.);
l_pos_z += l_space_before;
// Loop over number of repeats for this layer.
for (int j = 0; j < repeat; j++) {
string l_name = Form("layer%d", l_num);
double l_thickness = layering.layer(l_num - 1)->thickness(); // Layer's thickness.
double l_dim_x = tan_hphi* l_pos_z;
l_pos_z += l_thickness;
Position l_pos(0, 0, l_pos_z - l_thickness/2.); // Position of the layer.
double l_trd_x1 = l_dim_x;
double l_trd_x2 = l_dim_x + l_thickness*tan_hphi;
double l_trd_y1 = l_dim_y;
double l_trd_y2 = l_trd_y1;
double l_trd_z = l_thickness/2;
Trapezoid l_shape(l_trd_x1, l_trd_x2, l_trd_y1, l_trd_y2, l_trd_z);
Volume l_vol(l_name, l_shape, air);
DetElement layer(stave_det, l_name, det_id);
// Loop over the sublayers or slices for this layer.
int s_num = 1;
double s_pos_z = -(l_thickness / 2.);
for(xml_coll_t si(x_layer,_U(slice)); si; ++si) {
xml_comp_t x_slice = si;
string s_name = Form("slice%d", s_num);
double s_thick = x_slice.thickness();
double s_trd_x1 = l_dim_x + (s_pos_z + l_thickness/2)*tan_hphi;
double s_trd_x2 = l_dim_x + (s_pos_z + l_thickness/2 + s_thick)*tan_hphi;
double s_trd_y1 = l_trd_y1;
double s_trd_y2 = s_trd_y1;
double s_trd_z = s_thick/2.;
Trapezoid s_shape(s_trd_x1, s_trd_x2, s_trd_y1, s_trd_y2, s_trd_z);
Volume s_vol(s_name, s_shape, desc.material(x_slice.materialStr()));
DetElement slice(layer, s_name, det_id);
// build fibers
if (x_slice.hasChild(_Unicode(fiber))) {
buildFibers(desc, sens, s_vol, x_slice.child(_Unicode(fiber)), {s_trd_x1, s_thick, l_dim_y, hphi});
}
if ( x_slice.isSensitive() ) {
s_vol.setSensitiveDetector(sens);
}
s_vol.setAttributes(desc, x_slice.regionStr(), x_slice.limitsStr(), x_slice.visStr());
// Slice placement.
PlacedVolume slice_phv = l_vol.placeVolume(s_vol, Position(0, 0, s_pos_z + s_thick/2));
slice_phv.addPhysVolID("slice", s_num);
slice.setPlacement(slice_phv);
// Increment Z position of slice.
s_pos_z += s_thick;
++s_num;
}
// Set region, limitset, and vis of layer.
l_vol.setAttributes(desc, x_layer.regionStr(), x_layer.limitsStr(), x_layer.visStr());
PlacedVolume layer_phv = mod_vol.placeVolume(l_vol, l_pos);
layer_phv.addPhysVolID("layer", l_num);
layer.setPlacement(layer_phv);
// Increment to next layer Z position. Do not add space_between for the last layer
if (j < repeat - 1) {
l_pos_z += l_space_between;
}
++l_num;
}
}
}
// Phi start for a stave.
double phi = M_PI / nsides;
// Create nsides staves.
for (int i = 0; i < nsides; i++, phi -= dphi) { // i is module number
// Compute the stave position
Transform3D tr(RotationZYX(0, phi, M_PI*0.5), Translation3D(0, 0, 0));
PlacedVolume pv = envelope.placeVolume(mod_vol, tr);
pv.addPhysVolID("module", i + 1);
DetElement sd = (i == 0) ? stave_det : stave_det.clone(Form("stave%d", i));
sd.setPlacement(pv);
sdet.add(sd);
}
Solid support_frame_s;
// optional stave support
if (x_staves.hasChild("support")) {
xml_comp_t x_support = x_staves.child(_U(support));
double support_thickness = getAttrOrDefault(x_support, _U(thickness), 5.0 * cm);
double trd_x1_support = (2 * std::tan(hphi) * l_pos_z + support_thickness)/2;
// is the support on the inside surface?
bool is_inside_support = getAttrOrDefault<bool>(x_support, _Unicode(inside), true);
double trd_x1 = std::tan(hphi) * inner_r;
double trd_x2 = std::tan(hphi) * (l_pos_z + support_thickness);
double trd_y1 = x_dim.z()/2.;
// number of "beams" running the length of the stave.
int n_beams = getAttrOrDefault<int>(x_support, _Unicode(n_beams), 3);
double beam_thickness = support_thickness / 4.0; // maybe a parameter later...
trd_x1_support = (2 * std::tan(hphi) * (l_pos_z + beam_thickness)) / 2.;
double grid_size = getAttrOrDefault(x_support, _Unicode(grid_size), 25.0 * cm);
double beam_width = 2.0 * trd_x1_support / (n_beams + 1); // quick hack to make some gap between T beams
double cross_beam_thickness = support_thickness/4.0;
//double trd_x1_support = (2 * std::tan(hphi) * (inner_r + beam_thickness)) / 2.;
double trd_x2_support = trd_x2;
int n_cross_supports = std::floor((trd_y1-cross_beam_thickness)/grid_size);
Box beam_vert_s(beam_thickness / 2.0 , trd_y1, support_thickness / 2.0 );
Box beam_hori_s(beam_width / 2.0, trd_y1, beam_thickness / 2.0);
UnionSolid T_beam_s(beam_vert_s, beam_hori_s, Position(0, 0, -support_thickness / 2.0 + beam_thickness / 2.0));
// cross supports
Trapezoid trd_support(trd_x1_support,trd_x2_support,
beam_thickness / 2.0, beam_thickness / 2.0,
support_thickness / 2.0 - cross_beam_thickness/2.0);
UnionSolid support_array_start_s(T_beam_s,trd_support,Position(0,0,cross_beam_thickness/2.0));
for (int isup = 0; isup < n_cross_supports; isup++) {
support_array_start_s = UnionSolid(support_array_start_s, trd_support,
Position(0, -1.0 * isup * grid_size, cross_beam_thickness/2.0));
support_array_start_s = UnionSolid(support_array_start_s, trd_support,
Position(0, 1.0 * isup * grid_size, cross_beam_thickness/2.0));
}
support_array_start_s =
UnionSolid(support_array_start_s, beam_hori_s,
Position(-1.8 * 0.5*(trd_x1+trd_x2_support) / n_beams, 0, -support_thickness / 2.0 + beam_thickness / 2.0));
support_array_start_s =
UnionSolid(support_array_start_s, beam_hori_s,
Position(1.8 * 0.5*(trd_x1+trd_x2_support) / n_beams, 0, -support_thickness / 2.0 + beam_thickness / 2.0));
support_array_start_s =
UnionSolid(support_array_start_s, beam_vert_s, Position(-1.8 * 0.5*(trd_x1+trd_x2_support) / n_beams, 0, 0));
support_array_start_s =
UnionSolid(support_array_start_s, beam_vert_s, Position(1.8 * 0.5*(trd_x1+trd_x2_support) / n_beams, 0, 0));
support_frame_s = support_array_start_s;
Material support_mat = desc.material(x_support.materialStr());
Volume support_vol("support_frame_v", support_frame_s, support_mat);
support_vol.setVisAttributes(desc,x_support.visStr());
// figure out how to best place
auto pv = mod_vol.placeVolume(support_vol, Position(0.0, 0.0, l_pos_z + support_thickness / 2.0));
}
//l_pos_z += support_thickness;
// Set envelope volume attributes.
envelope.setAttributes(desc, x_det.regionStr(), x_det.limitsStr(), x_det.visStr());
return sdet;
}
void buildFibers(Detector& desc, SensitiveDetector sens, Volume &s_vol, xml_comp_t x_fiber,
std::tuple<double, double, double, double> dimensions)
{
auto [s_trd_x1, s_thick, s_length, hphi] = dimensions;
double f_radius = getAttrOrDefault(x_fiber, _U(radius), 0.1 * cm);
double f_spacing_x = getAttrOrDefault(x_fiber, _Unicode(spacing_x), 0.122 * cm);
double f_spacing_z = getAttrOrDefault(x_fiber, _Unicode(spacing_z), 0.134 * cm);
std::string f_id_grid = getAttrOrDefault(x_fiber, _Unicode(identifier_grid), "grid");
std::string f_id_fiber = getAttrOrDefault(x_fiber, _Unicode(identifier_fiber), "fiber");
// Set up the readout grid for the fiber layers
// Trapezoid is divided into segments with equal dz and equal number of divisions in x
// Every segment is a polygon that can be attached later to the lightguide
// The grid size is assumed to be ~2x2 cm (starting values). This is to be larger than
// SiPM chip (for GlueX 13mmx13mm: 4x4 grid 3mmx3mm with 3600 50×50 μm pixels each)
// See, e.g., https://arxiv.org/abs/1801.03088 Fig. 2d
// Calculate number of divisions
auto grid_div = getNdivisions(s_trd_x1, s_thick, 2.0*cm, 2.0*cm);
// Calculate polygonal grid coordinates (vertices)
auto grid_vtx = gridPoints(grid_div.first, grid_div.second, s_trd_x1, s_thick, hphi);
Tube f_tube(0, f_radius, s_length);
Volume f_vol("fiber_vol", f_tube, desc.material(x_fiber.materialStr()));
vector<int> f_id_count(grid_div.first*grid_div.second, 0);
auto f_pos = fiberPositions(f_radius, f_spacing_x, f_spacing_z, s_trd_x1, s_thick, hphi);
// std::cout << f_pos.size() << " lines, ~" << f_pos.front().size() << " fibers each line" << std::endl;
for (size_t il = 0; il < f_pos.size(); ++il) {
auto &line = f_pos[il];
if (line.empty()) {
continue;
}
double l_pos_y = line.front().y();
// use assembly as intermediate volume container to reduce number of daughter volumes
Assembly lfibers(Form("fiber_array_line_%d", il));
for (auto &p : line) {
int f_grid_id = -1;
int f_id = -1;
// Check to which grid fiber belongs to
for (auto &poly_vtx : grid_vtx) {
if (p.y() != l_pos_y) {
std::cerr << Form("Expected the same y position from a same line: %.2f, but got %.f", l_pos_y, p.y())
<< std::endl;
continue;
}
auto [grid_id, vtx_a, vtx_b, vtx_c, vtx_d] = poly_vtx;
double poly_x[4] = {vtx_a.x(), vtx_b.x(), vtx_c.x(), vtx_d.x()};
double poly_y[4] = {vtx_a.y(), vtx_b.y(), vtx_c.y(), vtx_d.y()};
double f_xy[2] = {p.x(), p.y()};
TGeoPolygon poly(4);
poly.SetXY(poly_x, poly_y);
poly.FinishPolygon();
if(poly.Contains(f_xy)) {
f_grid_id = grid_id;
f_id = f_id_count[grid_id];
f_id_count[grid_id]++;
}
}
if ( x_fiber.isSensitive() ) {
f_vol.setSensitiveDetector(sens);
}
f_vol.setAttributes(desc, x_fiber.regionStr(), x_fiber.limitsStr(), x_fiber.visStr());
// Fiber placement
// Transform3D f_tr(RotationZYX(0,0,M_PI*0.5),Position(p.x(), 0, p.y()));
// PlacedVolume fiber_phv = s_vol.placeVolume(f_vol, Position(p.x(), 0., p.y()));
PlacedVolume fiber_phv = lfibers.placeVolume(f_vol, Position(p.x(), 0., 0.));
fiber_phv.addPhysVolID(f_id_grid, f_grid_id + 1).addPhysVolID(f_id_fiber, f_id + 1);
}
Transform3D l_tr(RotationZYX(0,0,M_PI*0.5),Position(0., 0, l_pos_y));
s_vol.placeVolume(lfibers, l_tr);
}
}
DECLARE_DETELEMENT(athena_EcalBarrelInterlayers, create_detector)
// DECLARE_DETELEMENT(athena_EcalBarrelInterlayers, create_detector)