KVTrapezoidalStripDetector.cpp

#include "KVTrapezoidalStripDetector.h"
 
 
 
TGeoArb8* KVTrapezoidalStripDetector::make_arb8(const TString& name, double A, double B, double C, double dZ, double dX)
{
   double vert[] = {dX + C / 2, A / 2, dX + C / 2, -A / 2, dX - C / 2, -B / 2, dX - C / 2, B / 2, dX + C / 2, A / 2, dX + C / 2, -A / 2, dX - C / 2, -B / 2, dX - C / 2, B / 2};
   return new TGeoArb8(name, dZ / 2., vert);
}
 
 
 
 
TGeoArb8* KVTrapezoidalStripDetector::make_vert_strip_arb8(const TString& name, double y_A, double y_B, double x_AB, double x_C, double x_D, double dZ, double dX)
{
   double vert[] = {x_D + dX, y_A, x_C + dX, y_B, x_AB + dX, y_B, x_AB + dX, y_A, x_D + dX, y_A, x_C + dX, y_B, x_AB + dX, y_B, x_AB + dX, y_A};
   return new TGeoArb8(name, dZ / 2., vert);
}
 
 
 
 
TGeoArb8* KVTrapezoidalStripDetector::make_hori_strip_arb8(const TString& name, double x_AB, double y_A, double x_CD, double y_D, double dZ, double dX)
{
   double vert[] = {x_CD + dX, y_D, x_CD + dX, -y_D, x_AB + dX, -y_A, x_AB + dX, y_A, x_CD + dX, y_D, x_CD + dX, -y_D, x_AB + dX, -y_A, x_AB + dX, y_A};
   return new TGeoArb8(name, dZ / 2., vert);
}
 
 
 
 
double KVTrapezoidalStripDetector::Xcoord_of_frame_bottom(double Ycoord, double A, double B, double C)
{
   // for given Y coord (horizontal position) give X coord (vertical) of the 1 of the 3 sides
   // making up the bottom of the frame. in coordinates where trapeze centre is at X=0.
 
   if (Ycoord < -A / 2) Ycoord = -A / 2;
   if (Ycoord > A / 2) Ycoord = A / 2;
   if (TMath::Abs(Ycoord) < B / 2) {
      // on the bottom segment cc->dd
      return -C / 2;
   }
   if (Ycoord <= -B / 2 && Ycoord >= -A / 2) {
      // on left hand segment bb->cc
      return C / 2 - 2 * C / (A - B) * (Ycoord + A / 2);
   }
   if (Ycoord >= B / 2 && Ycoord <= A / 2) {
      // on right hand segment dd->aa
      return 2 * C / (A - B) * (Ycoord - B / 2) - C / 2;
   }
   return 0;
}
 
 
 
 
double KVTrapezoidalStripDetector::Ycoord_of_frame_side(double Xcoord, double A, double B, double C)
{
   // for a given vertical (X) position (between -C/2 and C/2) give the Y coordinate
   // on the side frame (between A/2 and B/2). We give the positive coordinate, the reflection
   // is given by the negative coordinate.
 
   return B / 2 + (A - B) / 2 / C * (Xcoord + C / 2);
}
 
 
 
 
KVTrapezoidalStripDetector::KVTrapezoidalStripDetector(const TString& name, double OF_A, double OF_B, double OF_C, double IF_A, double IF_B, double IF_C, double a, double dZ, StripDirection strip_direction, int N, double inter_strip)
   : TGeoVolumeAssembly(Form("DET_%s", name.Data()))
{
   /*
      OF_A, OF_B, OF_C = dimensions of outer frame (PCB) in cm
      IF_A, IF_B, IF_C = dimensions of inner frame (silicon) in cm
      a = distance between top of outer frame (OF_A) and top of inner frame (IF_A) in cm
      dZ = silicon thickness in cm
      N = number of strips
      inter_strip given in cm
   */
   KVMaterial si("Si"), cu("Cu"), al("Al");
   auto OF_trap = make_arb8(Form("OF_%s", name.Data()), OF_A, OF_B, OF_C, frame_thickness);
   // deduce b from a, OF_C and IF_C
   auto b = OF_C - a - IF_C;
   std::cout << "calculated b = " << b << " [cm]\n";
   dX_IF = 0.5 * (b - a);
   auto IF_trap = make_arb8(Form("IF_%s", name.Data()), IF_A, IF_B, IF_C, frame_thickness, dX_IF);
   auto cs = new TGeoCompositeShape(Form("FRAME_%s", name.Data()), Form("OF_%s-IF_%s", name.Data(), name.Data()));
   auto ofr = new TGeoVolume(Form("DEADZONE_FRAME_%s", name.Data()), cs, cu.GetGeoMedium());
   ofr->SetTransparency((Char_t)25);
 
   if (strip_direction == StripDirection::vertical) {
      // vertical strips
      double pitch = (IF_A - (N - 1) * inter_strip) / double(N);
      std::cout << "Strip width is " << pitch / KVUnits::um << " microns (" << inter_strip / KVUnits::um << " micron inter-strip)\n";
      double strip_B_y = IF_A / 2;
      double strip_A_y = strip_B_y - pitch;
      for (int strip = 0; strip < N; ++strip) {
         auto strip_C_x = Xcoord_of_frame_bottom(strip_B_y, IF_A, IF_B, IF_C);
         auto strip_D_x = Xcoord_of_frame_bottom(strip_A_y, IF_A, IF_B, IF_C);
         auto _s = make_vert_strip_arb8(Form("%s_STRIP_%d", name.Data(), strip), strip_A_y, strip_B_y, IF_C / 2, strip_C_x, strip_D_x, dZ, dX_IF);
         auto _svol = new TGeoVolume("SUBDET", _s, si.GetGeoMedium());
         //_svol->SetLineColor(kGray+1);
         AddNode(_svol, strip);
         strip_B_y -= (pitch + inter_strip);
         strip_A_y -= (pitch + inter_strip);
      }
      // add interstrip deadzones
      strip_B_y = IF_A / 2 - pitch;
      strip_A_y = strip_B_y - inter_strip;
      for (int strip = 1; strip < N; ++strip) {
         auto strip_C_x = Xcoord_of_frame_bottom(strip_B_y, IF_A, IF_B, IF_C);
         auto strip_D_x = Xcoord_of_frame_bottom(strip_A_y, IF_A, IF_B, IF_C);
         auto _s = make_vert_strip_arb8(Form("%s_INTERSTRIP_%d", name.Data(), strip), strip_A_y, strip_B_y, IF_C / 2, strip_C_x, strip_D_x, dZ, dX_IF);
         auto _svol = new TGeoVolume(Form("DEADZONE_%s_INTERSTRIP", name.Data()), _s, al.GetGeoMedium());
         //_svol->SetLineColor(kBlack);
         AddNode(_svol, strip + N);
         strip_B_y -= (pitch + inter_strip);
         strip_A_y -= (pitch + inter_strip);
      }
   }
   else { //  strip_direction==horizontal
      // horizontal strips: numbered from bottom (short/B side) to top (long/A side)
      double pitch = (IF_C - (N - 1) * inter_strip) / double(N);
      std::cout << "Strip width is " << pitch / KVUnits::um << " microns (" << inter_strip / KVUnits::um << " micron inter-strip)\n";
      double strip_AB_x = -IF_C / 2;
      double strip_CD_x = strip_AB_x + pitch;
      for (int strip = 0; strip < N; ++strip) {
         auto strip_AB_y = Ycoord_of_frame_side(strip_AB_x, IF_A, IF_B, IF_C);
         auto strip_CD_y = Ycoord_of_frame_side(strip_CD_x, IF_A, IF_B, IF_C);
         auto _s = make_hori_strip_arb8(Form("%s_STRIP_%d", name.Data(), strip), strip_AB_x, strip_AB_y, strip_CD_x, strip_CD_y, dZ, dX_IF);
         auto _svol = new TGeoVolume("SUBDET", _s, si.GetGeoMedium());
         //_svol->SetLineColor(kGray+1);
         AddNode(_svol, strip);
         strip_AB_x += (pitch + inter_strip);
         strip_CD_x += (pitch + inter_strip);
      }
      // add interstrip deadzones
      strip_AB_x = -IF_C / 2 + pitch;
      strip_CD_x = strip_AB_x + inter_strip;
      for (int strip = 1; strip < N; ++strip) {
         auto strip_AB_y = Ycoord_of_frame_side(strip_AB_x, IF_A, IF_B, IF_C);
         auto strip_CD_y = Ycoord_of_frame_side(strip_CD_x, IF_A, IF_B, IF_C);
         auto _s = make_hori_strip_arb8(Form("%s_INTERSTRIP_%d", name.Data(), strip), strip_AB_x, strip_AB_y, strip_CD_x, strip_CD_y, dZ, dX_IF);
         auto _svol = new TGeoVolume(Form("DEADZONE_%s_INTERSTRIP", name.Data()), _s, al.GetGeoMedium());
         //_svol->SetLineColor(kBlack);
         AddNode(_svol, strip + N);
         strip_AB_x += (pitch + inter_strip);
         strip_CD_x += (pitch + inter_strip);
      }
   }
   AddNode(ofr, 2 * N, new TGeoTranslation(0, 0, 0.5 * (dZ + frame_thickness)));
}
 
 
ClassImp(KVTrapezoidalStripDetector)