/**************************************************************************
* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
* *
* Author: The ALICE Off-line Project. *
* Contributors are mentioned in the code where appropriate. *
* *
* Permission to use, copy, modify and distribute this software and its *
* documentation strictly for non-commercial purposes is hereby granted *
* without fee, provided that the above copyright notice appears in all *
* copies and that both the copyright notice and this permission notice *
* appear in the supporting documentation. The authors make no claims *
* about the suitability of this software for any purpose. It is *
* provided "as is" without express or implied warranty. *
**************************************************************************/
/*
$Log$
Revision 1.15 2000/07/10 20:57:39 hristov
Update of TPC code and macros by M.Kowalski
Revision 1.14 2000/06/30 12:07:50 kowal2
Updated from the TPC-PreRelease branch
Revision 1.13.2.4 2000/06/26 07:39:42 kowal2
Changes to obey the coding rules
Revision 1.13.2.3 2000/06/25 08:38:41 kowal2
Splitted from AliTPCtracking
Revision 1.13.2.2 2000/06/16 12:58:13 kowal2
Changed parameter settings
Revision 1.13.2.1 2000/06/09 07:15:07 kowal2
Defaults loaded automatically (hard-wired)
Optional parameters can be set via macro called in the constructor
Revision 1.13 2000/05/15 10:00:30 kowal2
Corrected bug in the TPC geometry, thanks to Ivana Hrivnacova
Revision 1.12 2000/04/17 09:37:33 kowal2
removed obsolete AliTPCDigitsDisplay.C
Revision 1.11.8.2 2000/04/10 08:36:12 kowal2
Updated readout chambers
Some modifications to StepManager by M. Kowalski
Revision 1.11.8.1 2000/04/10 07:56:53 kowal2
Not used anymore - removed
Revision 1.11 1999/11/04 17:28:07 fca
Correct barrel part of HV Degrader
Revision 1.10 1999/10/14 16:52:08 fca
Only use PDG codes and not GEANT ones
Revision 1.9 1999/10/08 06:27:23 fca
Corrected bug in the HV degrader geometry, thanks to G.Tabary
Revision 1.8 1999/10/04 13:39:55 fca
Correct array index problem
Revision 1.7 1999/09/29 09:24:34 fca
Introduction of the Copyright and cvs Log
*/
//
///////////////////////////////////////////////////////////////////////////////
// //
// Time Projection Chamber version 3 -- detailed TPC and slow simulation //
//
//Begin_Html
/*
*/
//End_Html
// //
// //
///////////////////////////////////////////////////////////////////////////////
#include
#include
#include "AliTPCv3.h"
#include "AliRun.h"
#include "AliMC.h"
#include "AliConst.h"
#include "AliTPCDigitsArray.h"
#include"AliTPCParam.h"
#include"AliTPCParamSR.h"
#include "AliPDG.h"
#include
ClassImp(AliTPCv3)
//_____________________________________________________________________________
AliTPCv3::AliTPCv3(const char *name, const char *title) :
AliTPC(name, title)
{
//
// Standard constructor for Time Projection Chamber version 3
//
SetBufferSize(128000);
fIdSens=0;
SetGasMixt(2,20,10,-1,0.9,0.1,0.);
if (fTPCParam)
fTPCParam->Write(fTPCParam->GetTitle());
}
//_____________________________________________________________________________
void AliTPCv3::CreateGeometry()
{
//
// Creation of the TPC coarse geometry (version 3)
// The whole drift volume is sensitive
// Origin Marek Kowalski Cracow
//
//Begin_Html
/*
*/
//End_Html
//Begin_Html
/*
*/
//End_Html
Float_t dm[50];
Int_t *idtmed = fIdtmed->GetArray(); // TPC media
Int_t idrotm[120]; // rotation matrices
Int_t nRotMat = 0; // actual number of rotation matrices
//
// Mother volume (Air) - all volumes will be positioned in it
//
dm[0]=0.;
dm[1]=360.;
dm[2]=12.;
//
dm[3]= -283.7;
dm[4]= 66.2;
dm[5]= 277.95;
//
dm[6]= -255.6;
dm[7]= 66.2;
dm[8]= 277.95;
//
dm[9]= -73.3;
dm[10]= 59.0;
dm[11]= 277.95;
//
dm[12]= -73.3;
dm[13]= 56.9;
dm[14]= 277.95;
//
dm[15]= -72.1;
dm[16]= 56.9;
dm[17]= 277.95;
//
dm[18]= -72.1;
dm[19]= 60.65;
dm[20]= 277.95;
//
dm[21]= 72.1;
dm[22]= 60.65;
dm[23]= 277.95;
//
dm[24]= 72.1;
dm[25]= 56.9;
dm[26]= 277.95;
//
dm[27]= 73.3;
dm[28]= 56.9;
dm[29]= 277.95;
//
dm[30]= 73.3;
dm[31]= 60.65;
dm[32]= 277.95;
//
dm[33]= 250.4;
dm[34]= 66.0;
dm[35]= 277.95;
//
dm[36]= 283.7;
dm[37]= 66.0;
dm[38]= 277.95;
gMC->Gsvolu("TPC ","PCON",idtmed[0],dm,39);
//-------------------------------------------------------------------
// Tpc Outer INsulator (CO2)
//-------------------------------------------------------------------
dm[0]= 0.;
dm[1]= 360.;
dm[2]= 6.;
//
dm[3]= -253.6;
dm[4]= 258.;
dm[5]= 266.65;
//
dm[6]= -253.;
dm[7]= 258.;
dm[8]= 266.65;
dm[9]= -253.;
dm[10]= 258.;
dm[11]= 277.97;
dm[12]= 253.6;
dm[13]= 258.;
dm[14]= 277.97;
//
dm[15]= 253.6;
dm[16]= 265.2;
dm[17]= 277.95;
//
dm[18]= 255.6;
dm[19]= 265.2;
dm[20]= 277.95;
gMC->Gsvolu("TOIN","PCON",idtmed[3],dm,21);
//---------------------------------------------------------------
// shreds (G10) - TPC Rings
//---------------------------------------------------------------
gMC->Gsvolu("TPCR","TUBE",idtmed[12],dm,0);
dm[0]= 258.;
dm[1]= 266.65;
dm[2]= 0.3;
gMC->Gsposp("TPCR",1,"TOIN",0.,0.,-253.3,0,"ONLY",dm,3); // left bottom
//
dm[0]= 258.;
dm[1]= 270.9;
dm[2]= 0.3;
gMC->Gsposp("TPCR",2,"TOIN",0.,0.,253.3,0,"ONLY",dm,3); // right
//
dm[0]= 272.2;
dm[1]= 277.95;
dm[2]= 0.3;
gMC->Gsposp("TPCR",3,"TOIN",0.,0.,-250.7,0,"ONLY",dm,3); // left top
//----------------------------------------------------------------
// Tpc Outer Contaiment Vessel
// mother volume - Al, daughters - composite (sandwich)
//----------------------------------------------------------------
dm[0]= 0.;
dm[1]= 360.;
dm[2]=5.;
//
dm[3]= -250.4;
dm[4]= 272.2;
dm[5]= 277.95;
//
dm[6]= -248.4;
dm[7]= 272.2;
dm[8]= 277.95;
//
dm[9]= 253.6;
dm[10]= 272.2;
dm[11]= 277.95;
//
dm[12]= 253.6;
dm[13]= 265.2;
dm[14]= 277.95;
//
dm[15]= 255.6;
dm[16]= 265.2;
dm[17]= 277.95;
gMC->Gsvolu("TOCV","PCON",idtmed[4],dm,18);
// Daughter volumes
// Tpc SAndwich 1 - Al
dm[0]= 274.81;
dm[1]= 277.95;
dm[2]= 251.7;
gMC->Gsvolu("TSA1","TUBE",idtmed[4],dm,3);
// Tpc SAndwich 2 - Tedlar
dm[0] += 5.e-3;
dm[1] -= 5.e-3;
gMC->Gsvolu("TSA2","TUBE",idtmed[9],dm,3);
// Tpc SAndwich 3 - Kevlar
dm[0] += 5e-3;
dm[1] -= 5.e-3;
gMC->Gsvolu("TSA3","TUBE",idtmed[5],dm,3);
// Tpc SAndwich 4 - NOMEX honeycomb
dm[0] += 0.06;
dm[1] -= 0.06;
gMC->Gsvolu("TSA4","TUBE",idtmed[5],dm,3);
// 4->3->2->1->TOCV
gMC->Gspos("TSA4",1,"TSA3",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA3",1,"TSA2",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA2",1,"TSA1",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA1",1,"TOCV",0.,0.,2.6,0,"ONLY");
// TCOV-> TOIN
gMC->Gspos("TOCV",1,"TOIN",0.,0.,0.,0,"ONLY");
//-------------------------------------------------------
// Tpc Outer Field Cage
// mother volume - Al, daughters - composite (sandwich)
//-------------------------------------------------------
dm[0]=0.;
dm[1]=360.;
dm[2]=6.;
dm[3]= -253.;
dm[4]= 258.;
dm[5]= 277.95;
//
dm[6]= -251.;
dm[7]= 258.;
dm[8]= 277.95;
//
dm[9]= -251.;
dm[10]= 258.;
dm[11]= 260.05;
//
dm[12]= 251.;
dm[13]= 258.;
dm[14]= 260.05;
//
dm[15]= 251.;
dm[16]= 258.;
dm[17]= 260.05;
//
dm[18]= 253.;
dm[19]= 258.;
dm[20]= 270.9;
gMC->Gsvolu("TOFC","PCON",idtmed[4],dm,21);
// Daughter volumes
// Tpc SAndwich 5 - Al
dm[0]= 258.;
dm[1]= 260.05;
dm[2]= 251.7;
gMC->Gsvolu("TSA5","TUBE",idtmed[4],dm,3);
// Tpc SAndwich 6 - Tedlar
dm[0] += 5.e-3;
dm[1] -= 5.e-3;
gMC->Gsvolu("TSA6","TUBE",idtmed[9],dm,3);
// Tpc SAndwich 7 - Kevlar
dm[0] += 5.e-3;
dm[1] -= 5.e-3;
gMC->Gsvolu("TSA7","TUBE",idtmed[5],dm,3);
// Tpc SAndwich 8 - NOMEX
dm[0] += 0.02;
dm[1] -= 0.02;
gMC->Gsvolu("TSA8","TUBE",idtmed[6],dm,3);
// 8->7->6->5->TOFC
gMC->Gspos("TSA8",1,"TSA7",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA7",1,"TSA6",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA6",1,"TSA5",0.,0.,0.,0,"ONLY");
gMC->Gspos("TSA5",1,"TOFC",0.,0.,0.,0,"ONLY");
// TOFC->TOIN
gMC->Gspos("TOFC",1,"TOIN",0.,0.,0.,0,"ONLY");
// TOIN->TPC
gMC->Gspos("TOIN",1,"TPC ",0.,0.,0.,0,"ONLY");
//--------------------------------------------------------------------
// Tpc Inner INsulator (CO2)
//--------------------------------------------------------------------
dm[0]=0.;
dm[1]= 360.;
dm[2]= 15.;
//
dm[3]= -255.6;
dm[4]= 66.2;
dm[5]= 74.8;
//
Float_t tanL = (66.2-59.0)/(255.6-73.3); // tangent of the left cone part
dm[6]= -253.6;
dm[7]= 59.0+ (253.6-73.3)*tanL;
dm[8]= 74.8;
//
dm[9]= -253.6;
dm[10]= dm[7];
dm[11]= 79.2;
//
dm[12]= -73.3;
dm[13]= 59.0;
dm[14]= 79.2;
//
dm[15]= -73.3;
dm[16]= 56.9;
dm[17]= 79.2;
//
dm[18]= -72.1;
dm[19]= 59.6;
dm[20]= 79.2;
//
dm[21]= -72.1;
dm[22]= 60.65;
dm[23]= 79.2;
//
dm[24]= 72.1;
dm[25]= 60.65;
dm[26]= 79.2;
//
dm[27]= 72.1;
dm[28]= 59.6;
dm[29]= 79.2;
//
dm[30]= 73.3;
dm[31]= 56.9;
dm[32]= 79.2;
//
dm[33]= 73.3;
dm[34]= 59.0;
dm[35]= 79.2;
//
dm[36]= 250.4;
dm[37]= 66.0;
dm[38]= 79.2;
//
dm[39]= 253.0;
dm[40]= 66.0;
dm[41]= 79.2;
//
dm[42]= 253.0;
dm[43]= 75.3;
dm[44]= 79.2;
//
dm[45]= 253.6;
dm[46]= 75.3;
dm[47]= 79.2;
gMC->Gsvolu("TIIN","PCON",idtmed[3],dm,48);
//--------------------------------------------------------------------
// Tpc Inner Containment vessel, Left part
// mother volume - Al, daughter - composite (sandwich)
//--------------------------------------------------------------------
dm[0]= 0.;
dm[1]= 360.;
dm[2]= 8.;
//
dm[3]= -255.6;
dm[4]= 66.2;
dm[5]= 74.8;
//
Float_t cosL = 1./TMath::Sqrt(1.+tanL*tanL);
Float_t sandThick = 2.14; // cone composite thickness
//
dm[6]= -253.6;
dm[7]= 59.0 + (253.6-73.3)*tanL;
dm[8]= 74.8;
//
dm[9]= -253.6;
dm[10]= dm[7];
dm[11]= dm[7]+sandThick/cosL;
//
dm[12]= -75.6;
dm[13]= 59.0+(75.6-73.3)*tanL;
dm[14]= dm[13]+sandThick/cosL;
//
dm[15]= -75.6;
dm[16]= dm[13];
dm[17]= 60.65;
//
dm[18]= -73.3;
dm[19]= 59.0;
dm[20]= 60.65;
//
dm[21]= -73.3;
dm[22]= 56.9;
dm[23]= 60.65;
//
dm[24]= -72.1;
dm[25]= 56.9;
dm[26]= 60.65;
gMC->Gsvolu("TICL","PCON",idtmed[4],dm,27);
// Daughter volumes
// Tpc SAndwich 9 - Al
dm[0]= 0.;
dm[1]= 360.;
dm[2]= 2.;
//
dm[3]= - 254.3;
dm[4]= 59.0+(254.3-73.3)*tanL;
dm[5]= dm[4]+sandThick/cosL;
//
dm[6]= -78.3;
dm[7]= 59.0+(78.3-73.3)*tanL;
dm[8]= dm[7]+sandThick/cosL;
//
gMC->Gsvolu("TSA9","PCON",idtmed[4],dm,9);
// Tpc SAndwich 10 - Tedlar
dm[4]+= 5.e-3/cosL;
dm[5]-= 5.e-3/cosL;
//
dm[7]+= 5.e-3/cosL;
dm[8]+= 5.e-3/cosL;
gMC->Gsvolu("TS10","PCON",idtmed[9],dm,9);
// Tpc SAndwich 11 - Kevlar
dm[4]+= 5.e-3/cosL;
dm[5]-= 5.e-3/cosL;
//
dm[7]+= 5.e-3/cosL;
dm[8]+= 5.e-3/cosL;
gMC->Gsvolu("TS11","PCON",idtmed[5],dm,9);
// Tpc SAndwich 12 - NOMEX
dm[4]+= 0.06/cosL;
dm[5]-= 0.06/cosL;
//
dm[7]+= 0.06/cosL;
dm[8]+= 0.06/cosL;
gMC->Gsvolu("TS12","PCON",idtmed[6],dm,9);
// 12->11->10->9
gMC->Gspos("TS12",1,"TS11",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS11",1,"TS10",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS10",1,"TSA9",0.,0.,0.,0,"ONLY");
// TSA9->TICL
gMC->Gspos("TSA9",1,"TICL",0.,0.,0.,0,"ONLY");
//--------------------------------------------------------------------
// Tpc Inner Containment vessel, Right part
// mother volume - Al, daughter - composite (sandwich)
//--------------------------------------------------------------------
dm[0]= 0.;
dm[1]= 360.;
dm[2]=8.;
//
dm[3]= 72.1;
dm[4]= 56.9;
dm[5]= 60.65;
//
dm[6]= 73.3;
dm[7]= 56.9;
dm[8]= 60.65;
//
dm[9]= 73.3;
dm[10]= 59.0;
dm[11]= 60.65;
//
Float_t tanR = (66.0-59.0)/(250.5-73.3); // to avoid accuracy problems
Float_t cosR = 1./TMath::Sqrt(1.+tanR*tanR); //as above
//
dm[12]= 75.6;
dm[13]= 59.0+(75.6-73.3)*tanR;
dm[14]= 60.65;
//
dm[15]= 75.6;
dm[16]= dm[13];
dm[17]= dm[16]+sandThick/cosR;
//
dm[18]= 248.4;
dm[19]= 59.0+(248.4-73.3)*tanR;
dm[20]= dm[19]+sandThick/cosR;
//
dm[21]= 248.4;
dm[22]= dm[19];
dm[23]= 70.2;
//
dm[24]= 250.4;
dm[25]= 66.0;
dm[26]= 70.2;
gMC->Gsvolu("TICR","PCON",idtmed[4],dm,27);
// Daughter volumes
// Tpc SAndwich 13 - Al
dm[0]= 0.;
dm[1]= 360.;
dm[2]= 2.;
//
dm[3]= 78.3;
dm[4]= 59.0+(78.3-73.3)*tanR;
dm[5]= dm[4]+sandThick/cosR;
//
dm[6]= 249.1;
dm[7]= 59.0+(249.1-73.3)*tanR;
dm[8]= dm[7]+sandThick/cosR;
//
gMC->Gsvolu("TS13","PCON",idtmed[4],dm,9);
// Tpc SAndwich 14 - Tedlar
dm[4]+= 5.e-3/cosR;
dm[5]-= 5.e-3/cosR;
//
dm[7]+= 5.e-3/cosR;
dm[8]+= 5.e-3/cosR;
gMC->Gsvolu("TS14","PCON",idtmed[9],dm,9);
// Tpc SAndwich 15 - Kevlar
dm[4]+= 5.e-3/cosR;
dm[5]-= 5.e-3/cosR;
//
dm[7]+= 5.e-3/cosR;
dm[8]+= 5.e-3/cosR;
gMC->Gsvolu("TS15","PCON",idtmed[5],dm,9);
// Tpc SAndwich 16 - NOMEX
dm[4]+= 0.06/cosR;
dm[5]-= 0.06/cosR;
//
dm[7]+= 0.06/cosR;
dm[8]+= 0.06/cosR;
gMC->Gsvolu("TS16","PCON",idtmed[6],dm,9);
// 16->15->14->13
gMC->Gspos("TS16",1,"TS15",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS15",1,"TS14",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS14",1,"TS13",0.,0.,0.,0,"ONLY");
// TS12->TICR
gMC->Gspos("TS13",1,"TICR",0.,0.,0.,0,"ONLY");
//------------------------------------------------------
// Tpc Inner Field Cage
// mother volume - Al, daughters - composite (sandwich)
//------------------------------------------------------
dm[0]= 0.;
dm[1]= 360.;
dm[2]=6.;
//
dm[3]= -253.0;
dm[4]= 70.7;
dm[5]= 79.2;
//
dm[6]= -251.0;
dm[7]= 70.7;
dm[8]= 79.2;
//
dm[9]= -251.0;
dm[10]= 77.15;
dm[11]= 79.2;
//
dm[12]= 251.0;
dm[13]= 77.15;
dm[14]= 79.2;
//
dm[15]= 251.0;
dm[16]= 66.0;
dm[17]= 79.2;
//
dm[18]= 253.0;
dm[19]= 66.0;
dm[20]= 79.2;
gMC->Gsvolu("TIFC","PCON",idtmed[4],dm,21);
// Daughter volumes
// Tpc Sandwich 17 - Al
dm[0]= 77.15;
dm[1]= 79.2;
dm[2]= 251.7;
gMC->Gsvolu("TS17","TUBE",idtmed[4],dm,3);
// Tpc Sandwich 18 - Tedlar
dm[0]+= 5.e-3;
dm[1]-= 5.e-3;
gMC->Gsvolu("TS18","TUBE",idtmed[9],dm,3);
// Tpc Sandwich 19 - Kevlar
dm[0]+= 5.e-3;
dm[1]-= 5.e-3;
gMC->Gsvolu("TS19","TUBE",idtmed[5],dm,3);
// Tpc Sandwich 20 - NOMEX
dm[0]+= 0.06;
dm[1]-= 0.06;
gMC->Gsvolu("TS20","TUBE",idtmed[6],dm,3);
// 20->19->18->17
gMC->Gspos("TS20",1,"TS19",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS19",1,"TS18",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS18",1,"TS17",0.,0.,0.,0,"ONLY");
// TS17->TIFC
gMC->Gspos("TS17",1,"TIFC",0.,0.,0.,0,"ONLY");
// TPC Rings
dm[0]= 70.7;
dm[1]= 79.2;
dm[2]= 0.3;
gMC->Gsposp("TPCR",4,"TIIN",0.,0.,-253.3,0,"ONLY",dm,3);
dm[0]= 66.0;
dm[1]= 70.2;
gMC->Gsposp("TPCR",5,"TIIN",0.,0.,250.7,0,"ONLY",dm,3);
dm[0]= 75.3;
dm[1]= 79.2;
gMC->Gsposp("TPCR",6,"TIIN",0.,0.,253.3,0,"ONLY",dm,3);
// TICL->TIIN
gMC->Gspos("TICL",1,"TIIN",0.,0.,0.,0,"ONLY");
// TICR->TIIN
gMC->Gspos("TICR",1,"TIIN",0.,0.,0.,0,"ONLY");
// TIFC->TIIN
gMC->Gspos("TIFC",1,"TIIN",0.,0.,0.,0,"ONLY");
// Tpc Sandwich 21 - Al (central barrel)
dm[0]= 77.15;
dm[1]= 79.2;
dm[2]= 75.2;
gMC->Gsvolu("TS21","TUBE",idtmed[4],dm,3);
// Tpc Sandwich 22 - Tedlar (central barrel)
dm[0]+= 5.e-3;
dm[1]-= 5.e-3;
gMC->Gsvolu("TS22","TUBE",idtmed[9],dm,3);
// Tpc Sandwich 23 - Kevlar (central barrel)
dm[0]+= 5.e-3;
dm[1]-= 5.e-3;
gMC->Gsvolu("TS23","TUBE",idtmed[5],dm,3);
// Tpc Sandwich 24 - NOMEX (central barrel)
dm[0]+= 0.02;
dm[1]-= 0.02;
gMC->Gsvolu("TS24","TUBE",idtmed[6],dm,3);
// 24->23->22->21
gMC->Gspos("TS24",1,"TS23",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS23",1,"TS22",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS22",1,"TS21",0.,0.,0.,0,"ONLY");
gMC->Gspos("TS21",1,"TIIN",0.,0.,0.,0,"ONLY");
// put everything into the TPC
gMC->Gspos("TIIN",1,"TPC ",0.,0.,0.,0,"ONLY");
//---------------------------------------------------------
// Tpc Dift Gas volume Nonsensitive (Ne-CO2 90/10)
// and its daughters (HV membrane, rods, readout chambers)
//---------------------------------------------------------
dm[0]= 79.2;
dm[1]= 258.0;
dm[2]= 253.6;
gMC->Gsvolu("TDGS","TUBE",idtmed[2],dm,3);
// sector opening angles
Float_t innerOpenAngle = fTPCParam->GetInnerAngle();
// sector angle shift
Float_t innerAngleShift = fTPCParam->GetInnerAngleShift();
// number of sectors
Int_t nInnerSector = fTPCParam->GetNInnerSector()/2;
Int_t nOuterSector = fTPCParam->GetNOuterSector()/2;
// All above parameters are identical for inner and outer
// sectors. The distinction is kept for the historical reasons
// and eventually will disappear.
Float_t tanAlpha = TMath::Tan(0.5*innerOpenAngle);
Float_t cosAlpha = TMath::Sqrt(1.+tanAlpha*tanAlpha);
Float_t space;
//-------------------------------------------------------------------------
// Tpc Inner Readout Chambers
//-------------------------------------------------------------------------
dm[0]= 14.483;
dm[1]= 23.3345;
dm[2]= 1.6; // thickness
dm[3]= 25.1;
gMC->Gsvolu("TIRC","TRD1",idtmed[4],dm,4);
// this volume will be positioned in the empty space
// of the end-cap to avoid overlaps
dm[0]= 13.7305;
dm[1]= 21.1895;
dm[2]= 2.25;
dm[3]= 21.15;
gMC->Gsvolu("TIC1","TRD1",idtmed[4],dm,4);
//------------------------------------------------
// Tpc Inner readout chamber Pad Plane
//------------------------------------------------
dm[0]= 14.483;
dm[1]= 23.3345;
dm[2]= 0.5;
dm[3]= 25.1;
gMC->Gsvolu("TIPP","TRD1",idtmed[12],dm,4);
//
dm[0] -= 1.218511934;
dm[1] -= 1.218511934;
dm[2] = 0.35;
gMC->Gsvolu("TIC3","TRD1",idtmed[2],dm,4);
gMC->Gspos("TIC3",1,"TIPP",0.,0.15,0.,0,"ONLY");
gMC->Gspos("TIPP",1,"TIRC",0.,1.1,0.,0,"ONLY");
//----------------------------------------------
// Tpc Readout Chambers Empty spaces - for both
// inner and outer sectors
//----------------------------------------------
gMC->Gsvolu("TRCE","TRD1",idtmed[0],dm,0);
// Inner sector - 4 spaces
dm[3] = 4.7625;
dm[0] = 12.472;
Float_t rr = 90.52;
Float_t zz;
zz= -12.7875;
space = rr*tanAlpha-dm[0];
for(Int_t nsLow=0;nsLow<4;nsLow++){
rr += 9.525;
dm[1]= rr*tanAlpha - space;
dm[2]=0.8;
gMC->Gsposp("TRCE",nsLow+1,"TIRC",0.,-0.8,zz,0,"ONLY",dm,4);
//
dm[2]= 1.2;
gMC->Gsposp("TRCE",nsLow+5,"TIC1",0.,1.05,zz-2.1,0,"ONLY",dm,4);
rr += 0.4;
dm[0] = rr*tanAlpha - space;
zz += (0.4+9.525);
}
dm[0]= 12.472;
// dm[1] - this is the dm[1] from the previous TRCE
dm[2]= 1.05;
dm[3]= 19.65;
gMC->Gsposp("TRCE",9,"TIC1",0.,-1.,0.,0,"ONLY",dm,4);
//
// TPc Space for Connectors
//
dm[0]= .3;
dm[1]= .3;
dm[2]= 4.5;
gMC->Gsvolu("TPSC","BOX ",idtmed[0],dm,3);
// TPC Connectors
dm[0]= .25;
dm[1]= .15;
dm[2]= 3.75;
gMC->Gsvolu("TPCC","BOX ",idtmed[13],dm,3);
gMC->Gspos("TPCC",1,"TPSC",0.,0.15,0.,0,"ONLY");
zz = -12.7875;
Float_t alpha;
Float_t astep;
Float_t phi1,phi2,phi3,theta1,theta2,theta3; // rotation angles
// inner part of the inner sector - 2 x 20 holes
astep = 20.00096874/19.;
alpha = 10.00048437-astep;
Float_t x1,x2;
x1 = 13.31175725;
x1 -= 0.996357832;
x2 = 15.06180253;
x2 -= 1.163028812;
Int_t ncon;
for(ncon=0;ncon<20;ncon++){
phi1 = 0.;
theta1 = 90.+alpha;
phi2=90.;
theta2 = 90.;
phi3 = (alpha>0) ? 0. : 180.;
theta3 = TMath::Abs(alpha);
AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
gMC->Gspos("TPSC",ncon+1,"TIRC",x1,0.3,-12.7875,idrotm[nRotMat],"ONLY");
gMC->Gspos("TPSC",ncon+21,"TIRC",x2,0.3,-2.8625,idrotm[nRotMat],"ONLY");
x1 -= 1.296357833;
x2 -= 1.463028812;
alpha -= astep;
nRotMat++;
}
// outer part of the inner sector - 2 x 25 holes
astep = 20.00096874/24.;
alpha = 10.00048437-astep;
x1 = 16.81184781;
x1 -= 1.016295986;
x2 = 18.5618931;
x2 -= 1.150914854;
for(ncon=0;ncon<25;ncon++){
phi1 = 0.;
theta1 = 90.+alpha;
phi2=90.;
theta2 = 90.;
phi3 = (alpha>0) ? 0. : 180.;
theta3 = TMath::Abs(alpha);
AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
gMC->Gspos("TPSC",ncon+41,"TIRC",x1,0.3,7.0625,idrotm[nRotMat],"ONLY");
gMC->Gspos("TPSC",ncon+66,"TIRC",x2,0.3,16.9875,idrotm[nRotMat],"ONLY");
x1 -= 1.316295986;
x2 -= 1.450914854;
alpha -= astep;
nRotMat++;
}
//--------------------------------------------------------------------------
// TPC Outer Readout Chambers
// this is NOT a final design
//--------------------------------------------------------------------------
dm[0]= 23.3875;
dm[1]= 43.524;
dm[2]= 1.5; //thickness
dm[3]= 57.1;
gMC->Gsvolu("TORC","TRD1",idtmed[4],dm,4);
//------------------------------------------------
// Tpc Outerr readout chamber Pad Plane
//------------------------------------------------
dm[2]= 0.5;
gMC->Gsvolu("TOPP","TRD1",idtmed[12],dm,4);
dm[0] -= 1.218511934;
dm[1] -= 1.218511934;
dm[2] = 0.35;
gMC->Gsvolu("TOC3","TRD1",idtmed[2],dm,4);
gMC->Gspos("TOC3",1,"TOPP",0.,0.15,0.,0,"ONLY");
gMC->Gspos("TOPP",1,"TORC",0.,1.0,0.,0,"ONLY");
// empty space
dm[0]= 21.035;
dm[1]= 38.7205;
dm[2]= 0.7;
dm[3]= 50.15;
gMC->Gsposp("TRCE",10,"TORC",0.,-0.8,-2.15,0,"ONLY",dm,4);
dm[0]= 22.2935;
dm[1]= 40.5085;
dm[2]= 2.25;
dm[3]= 51.65;
gMC->Gsvolu("TOC1","TRD1",idtmed[4],dm,4);
dm[0]= 21.35;
dm[1]= 38.7205;
dm[2]= 2.25;
dm[3]= 50.15;
gMC->Gsposp("TRCE",11,"TOC1",0.,0.,0.,0,"ONLY",dm,4);
//-----------------------------------------------
// Tpc Services Support Wheel
//-----------------------------------------------
dm[0]=0.;
dm[1]=360.;
dm[2]=18.;
dm[3]=2.;
dm[4]= -5.;
dm[5]= 77.017;
dm[6]= 255.267;
dm[7]= 5.;
dm[8]= dm[5];
dm[9]= dm[6];
gMC->Gsvolu("TSSW","PGON",idtmed[4],dm,10);
// Tpc Services Wheel Cover
dm[4]= -0.5;
dm[7]= 0.5;
gMC->Gsvolu("TSWC","PGON",idtmed[4],dm,10);
// Tpc Service wheel Cover Empty space
dm[0]= 10.99;
dm[1]= 39.599;
dm[2]= .5;
dm[3]= 81.125;
gMC->Gsvolu("TSCE","TRD1",idtmed[0],dm,4);
// Tpc services Wheel Empty Spaces
dm[0]= 13.18017507;
dm[1]= 44.61045938;
dm[2]= 4.;
dm[3]= 89.125;
gMC->Gsvolu("TWES","TRD1",idtmed[0],dm,4);
// Tpc Services Wheel Bars
gMC->Gsvolu("TSWB","TRD1",idtmed[4],dm,0);
// bars-> TWES
dm[2]= 4.;
dm[3]= .4;
dm[0]= 13.8149522;
dm[1]= 13.95601379;
gMC->Gsposp("TSWB",1,"TWES",0.,0.,-85.125,0,"ONLY",dm,4);
dm[0]= 43.83462067;
dm[1]= 43.97568225;
gMC->Gsposp("TSWB",2,"TWES",0.,0.,85.125,0,"ONLY",dm,4);
// TPc ELectronics - right now 30% X0 Si
dm[0]= 14.03813696;
dm[1]= 43.3524075;
dm[2]= 1.404;
dm[3]= 83.125;
gMC->Gsvolu("TPEL","TRD1",idtmed[11],dm,4);
gMC->Gspos("TPEL",1,"TWES",0.,0.,0.,0,"ONLY");
//--------------------------------------------------------------------------
// End caps
//--------------------------------------------------------------------------
// TPc Main Wheel - Al
dm[0]= 75.3;
dm[1]= 264.8;
dm[2]= 3.0;
gMC->Gsvolu("TPMW","TUBE",idtmed[4],dm,3);
// TPc Extra Wheel (to avoid overlapping) - Al
dm[0]= 264.8;
dm[1]= 277.0;
dm[2]= 1.95;
gMC->Gsvolu("TPEW","TUBE",idtmed[4],dm,3);
//--------------------------------------------------------------------------
// Tpc Empty Space for the Readout chambers
//--------------------------------------------------------------------------
Float_t rLow= 86.2;
Float_t rUp= 243.5;
Float_t dR = 0.5*(rUp-rLow);
space= 1.4/cosAlpha; // wheel ribs are 2.8 cm wide
dm[0]= rLow*tanAlpha-space;
dm[1]= rUp*tanAlpha-space;
dm[2]= 3.0;
dm[3]= dR;
gMC->Gsvolu("TESR","TRD1",idtmed[0],dm,4);
// TIC1->TESR
gMC->Gspos("TIC1",1,"TESR",0.,0.75,-dR+23.97,0,"ONLY");
// TOC1->TESR
gMC->Gspos("TOC1",1,"TESR",0.,0.75,dR-55.02,0,"ONLY");
// Tpc Empty Space Bars - Al (daughters of TESR)
Float_t zBar;
gMC->Gsvolu("TESB","TRD1",idtmed[4],dm,0);
// lower bar
dm[0]= rLow*tanAlpha-space;
dm[1]= 88.7*tanAlpha-space;
dm[2]= 0.95;
dm[3]= 1.275;
zBar = -dR+dm[3];
gMC->Gsposp("TESB",1,"TESR",0.,2.05,zBar,0,"ONLY",dm,4);
// middle bar
dm[0]= 131.65*tanAlpha-space;
dm[1]= 136.5*tanAlpha-space;
dm[3]= 2.425;
zBar = -dR +131.65+dm[3]-rLow;
gMC->Gsposp("TESB",2,"TESR",0.,2.05,zBar,0,"ONLY",dm,4);
// upper bar
dm[0]= 240.4*tanAlpha-space;
dm[1]= rUp*tanAlpha-space;
dm[3]= 1.55;
zBar = dR-dm[3];
gMC->Gsposp("TESB",3,"TESR",0.,2.05,zBar,0,"ONLY",dm,4);
// positioning of the empty spaces into the main wheel
Float_t rCenter,xc,yc;
Float_t rInner,rOuter; // center of the inner and outer chamber
rCenter = rLow+dR;
rInner = 108.07;
rOuter = 190.68;
for(Int_t ns=0; ns 360.) phi1 -= 360.;
theta1 = 90.;
phi2 = 90.;
theta2 = 180.;
phi3 = ns * innerOpenAngle + innerAngleShift;
phi3 *= kRaddeg; // in degrees
phi3 = (Float_t)TMath::Nint(phi3);
if(phi3 > 360.) phi3 -= 360.;
theta3 = 90.;
// "holes"->End plate
xc = rCenter*TMath::Cos(phi3*kDegrad);
yc = rCenter*TMath::Sin(phi3*kDegrad);
AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
gMC->Gspos("TESR",ns+1,"TPMW",xc,yc,0.,idrotm[nRotMat],"ONLY");
// TSCE->TSWC (services wheel volumes)
xc = 166.142*TMath::Cos(phi3*kDegrad);
yc = 166.142*TMath::Sin(phi3*kDegrad);
gMC->Gspos("TSCE",ns+1,"TSWC",xc,yc,0.,idrotm[nRotMat],"ONLY");
gMC->Gspos("TWES",ns+1,"TSSW",xc,yc,0.,idrotm[nRotMat],"ONLY");
// readout chambers->TDGS (drift gas)
xc = rInner*TMath::Cos(phi3*kDegrad);
yc = rInner*TMath::Sin(phi3*kDegrad);
gMC->Gspos("TIRC",ns+1,"TDGS",xc,yc,252.,idrotm[nRotMat],"ONLY");
xc = rOuter*TMath::Cos(phi3*kDegrad);
yc = rOuter*TMath::Sin(phi3*kDegrad);
gMC->Gspos("TORC",ns+1,"TDGS",xc,yc,252.1,idrotm[nRotMat],"ONLY");
nRotMat++;
theta2 = 0.; // reflection
AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
xc = rInner*TMath::Cos(phi3*kDegrad);
yc = rInner*TMath::Sin(phi3*kDegrad);
gMC->Gspos("TIRC",ns+nInnerSector+1,"TDGS",xc,yc,-252.,idrotm[nRotMat],"ONLY");
xc = rOuter*TMath::Cos(phi3*kDegrad);
yc = rOuter*TMath::Sin(phi3*kDegrad);
gMC->Gspos("TORC",ns+nOuterSector+1,"TDGS",xc,yc,-252.1,idrotm[nRotMat],"ONLY");
nRotMat++;
}
// reflection matrix
theta1 = 90.;
phi1 = 0.;
theta2 = 90.;
phi2 = 270.;
theta3 = 180.;
phi3 = 0.;
AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
// TPMW->TPC
gMC->Gspos("TPMW",1,"TPC ",0.,0.,256.6,0,"ONLY");
gMC->Gspos("TPMW",2,"TPC ",0.,0.,-256.6,idrotm[nRotMat],"ONLY");
gMC->Gspos("TPEW",1,"TPC ",0.,0.,257.65,0,"ONLY");
gMC->Gspos("TPEW",2,"TPC ",0.,0.,-257.65,0,"ONLY");
//-------------------------------------------------------
// Tpc High Voltage Membrane - NOMEX honeycomb
//-------------------------------------------------------
dm[0]=0.,
dm[1]=360.;
dm[2]=18.;
dm[3]=2.;
//
dm[4]= -0.3;
dm[5]= 81.156;
dm[6]= 253.386;
//
dm[7]= 0.3;
dm[8]= dm[5];
dm[9]= dm[6];
gMC->Gsvolu("THVM","PGON",idtmed[6],dm,10);
gMC->Gspos("THVM",1,"TDGS",0.,0.,0.,0,"ONLY");
//----------------------------------------------------------
// TPc Support Rods - MAKROLON
//----------------------------------------------------------
dm[0]= 0.9;
dm[1]= 1.2;
dm[2]= 126.65;
gMC->Gsvolu("TPSR","TUBE",idtmed[7],dm,3);
for(Int_t nrod=1;nrod<18;nrod++){
Float_t angle=innerOpenAngle*(Float_t)nrod;
xc=82.4*TMath::Cos(angle);
yc=82.4*TMath::Sin(angle);
gMC->Gspos("TPSR",nrod,"TDGS",xc,yc,126.95,0,"ONLY");
gMC->Gspos("TPSR",nrod+17,"TDGS",xc,yc,-126.95,0,"ONLY");
xc=254.2*TMath::Cos(angle);
yc=254.2*TMath::Sin(angle);
gMC->Gspos("TPSR",nrod+34,"TDGS",xc,yc,126.95,0,"ONLY");
gMC->Gspos("TPSR",nrod+51,"TDGS",xc,yc,-126.95,0,"ONLY");
}
//----------------------------------------------------------
// Tpc High Voltage rod - MAKROLON + Copper cable
//----------------------------------------------------------
// rod with cable (Left)
dm[0]=0.;
dm[1]=2.25;
dm[2]=126.65;
gMC->Gsvolu("THVL","TUBE",idtmed[7],dm,3);
// HV cable
dm[0]=0.;
dm[1]=0.3;
dm[2]=126.65;
gMC->Gsvolu("THVC","TUBE",idtmed[10],dm,3);
// empty space
dm[0]=0.3;
dm[1]=1.;
dm[2]=126.65;
gMC->Gsvolu("THVE","TUBE",idtmed[1],dm,3);
gMC->Gspos("THVC",1,"THVL",0.,0.,0.,0,"ONLY");
gMC->Gspos("THVE",1,"THVL",0.,0.,0.,0,"ONLY");
// rod without cable
dm[0]=1.8;
dm[1]=2.25;
dm[2]=126.65;
gMC->Gsvolu("THVR","TUBE",idtmed[7],dm,3);
gMC->Gspos("THVL",1,"TDGS",82.4,0.,-126.95,0,"ONLY");
gMC->Gspos("THVL",2,"TDGS",254.2,0.,-126.95,0,"ONLY");
gMC->Gspos("THVR",1,"TDGS",82.4,0.,126.95,0,"ONLY");
gMC->Gspos("THVR",2,"TDGS",254.2,0.,126.95,0,"ONLY");
gMC->Gspos("TDGS",1,"TPC ",0.,0.,0.,0,"ONLY");
// services wheel cover -> wheel
gMC->Gspos("TSWC",1,"TSSW",0.,0.,4.5,0,"ONLY");
gMC->Gspos("TSWC",2,"TSSW",0.,0.,-4.5,0,"ONLY");
// put the wheel into the TPC
gMC->Gspos("TSSW",1,"TPC ",0.,0.,278.7,0,"ONLY");
gMC->Gspos("TSSW",2,"TPC ",0.,0.,-278.7,0,"ONLY");
gMC->Gsord("TPMW",6);
gMC->Gsord("TSSW",6);
gMC->Gsord("TSWC",6);
// put the TPC into ALIC (main mother volume)
gMC->Gspos("TPC ",1,"ALIC",0.,0.,0.,0,"ONLY");
} // end of function
//_____________________________________________________________________________
void AliTPCv3::DrawDetector()
{
//
// Draw a shaded view of the Time Projection Chamber version 1
//
// Set everything unseen
gMC->Gsatt("*", "seen", -1);
//
// Set ALIC mother transparent
gMC->Gsatt("ALIC","SEEN",0);
//
// Set the volumes visible
//
gMC->Gsatt("TPC ","SEEN",0);
gMC->Gsatt("TOIN","SEEN",1);
gMC->Gsatt("TOIN","COLO",7);
gMC->Gsatt("TPCR","SEEN",0);
gMC->Gsatt("TOCV","SEEN",1);
gMC->Gsatt("TOCV","COLO",4);
gMC->Gsatt("TSA1","SEEN",0);
gMC->Gsatt("TSA2","SEEN",0);
gMC->Gsatt("TSA3","SEEN",0);
gMC->Gsatt("TSA4","SEEN",0);
gMC->Gsatt("TOFC","SEEN",1);
gMC->Gsatt("TOFC","COLO",4);
gMC->Gsatt("TSA5","SEEN",0);
gMC->Gsatt("TSA6","SEEN",0);
gMC->Gsatt("TSA7","SEEN",0);
gMC->Gsatt("TSA8","SEEN",0);
gMC->Gsatt("TIIN","COLO",7);
gMC->Gsatt("TIIN","SEEN",1);
gMC->Gsatt("TICL","SEEN",0);
gMC->Gsatt("TSA9","SEEN",0);
gMC->Gsatt("TS10","SEEN",0);
gMC->Gsatt("TS11","SEEN",0);
gMC->Gsatt("TS12","SEEN",0);
gMC->Gsatt("TICR","SEEN",0);
gMC->Gsatt("TS13","SEEN",0);
gMC->Gsatt("TS14","SEEN",0);
gMC->Gsatt("TS15","SEEN",0);
gMC->Gsatt("TS16","SEEN",0);
gMC->Gsatt("TIFC","SEEN",1);
gMC->Gsatt("TIFC","COLO",4);
gMC->Gsatt("TS17","SEEN",0);
gMC->Gsatt("TS18","SEEN",0);
gMC->Gsatt("TS19","SEEN",0);
gMC->Gsatt("TS20","SEEN",0);
gMC->Gsatt("TS21","SEEN",0);
gMC->Gsatt("TS22","SEEN",0);
gMC->Gsatt("TS23","SEEN",0);
gMC->Gsatt("TS24","SEEN",0);
gMC->Gsatt("TDGS","SEEN",0);
gMC->Gsatt("TIRC","SEEN",0);
gMC->Gsatt("TIC1","SEEN",1);
gMC->Gsatt("TIPP","SEEN",0);
gMC->Gsatt("TIC3","SEEN",0);
gMC->Gsatt("TRCE","SEEN",0);
gMC->Gsatt("TPSC","SEEN",0);
gMC->Gsatt("TPCC","SEEN",0);
gMC->Gsatt("TORC","SEEN",0);
gMC->Gsatt("TOPP","SEEN",0);
gMC->Gsatt("TOC3","SEEN",0);
gMC->Gsatt("TOC1","SEEN",1);
gMC->Gsatt("TSSW","SEEN",1);
gMC->Gsatt("TSWC","SEEN",1);
gMC->Gsatt("TSCE","SEEN",1);
gMC->Gsatt("TSSW","COLO",3);
gMC->Gsatt("TSWC","COLO",3);
gMC->Gsatt("TSCE","COLO",6);
gMC->Gsatt("TWES","SEEN",0);
gMC->Gsatt("TSWB","SEEN",0);
gMC->Gsatt("TPEL","SEEN",0);
gMC->Gsatt("TPMW","SEEN",1);
gMC->Gsatt("TPEW","SEEN",1);
gMC->Gsatt("TESR","SEEN",1);
gMC->Gsatt("TPMW","COLO",12);
gMC->Gsatt("TPEW","COLO",12);
gMC->Gsatt("TWES","COLO",5);
gMC->Gsatt("TIC1","COLO",5);
gMC->Gsatt("TOC1","COLO",5);
gMC->Gsatt("TESB","SEEN",0);
gMC->Gsatt("TPLS","SEEN",0);
gMC->Gsatt("TPUS","SEEN",0);
gMC->Gsatt("TPSS","SEEN",0);
gMC->Gsatt("THVM","SEEN",1);
gMC->Gsatt("THVM","COLO",11);
gMC->Gsatt("TPSR","SEEN",0);
gMC->Gsatt("THVL","SEEN",0);
gMC->Gsatt("THVC","SEEN",0);
gMC->Gsatt("THVE","SEEN",0);
gMC->Gsatt("THVR","SEEN",0);
//
gMC->Gdopt("hide", "on");
gMC->Gdopt("shad", "on");
gMC->Gsatt("*", "fill", 7);
gMC->SetClipBox(".");
gMC->SetClipBox("TPMW",-300,300,-300,300,254.,270.);
gMC->SetClipBox("TESR",-300,300,-300,300,254.,270.);
gMC->SetClipBox("TSSW",-300,300,-300,300,283.,284.);
gMC->SetClipBox("TSWC",-300,300,-300,300,283.,284.);
gMC->SetClipBox("*", 0, 300, -300, 300, -290, 290);
gMC->DefaultRange();
gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025);
gMC->Gdhead(1111, "Time Projection Chamber");
gMC->Gdman(18, 4, "MAN");
gMC->Gdopt("hide","off");
}
//_____________________________________________________________________________
void AliTPCv3::CreateMaterials()
{
//
// Define materials for version 2 of the Time Projection Chamber
//
//
AliTPC::CreateMaterials();
}
//_____________________________________________________________________________
void AliTPCv3::Init()
{
//
// Initialises version 3 of the TPC after that it has been built
//
Int_t *idtmed = fIdtmed->GetArray();
AliTPC::Init();
fIdSens=gMC->VolId("TDGS"); // drift gas as a sensitive volume
gMC->SetMaxNStep(30000); // max. number of steps increased
gMC->Gstpar(idtmed[2],"LOSS",5);
printf("*** TPC version 3 initialized ***\n");
printf("Maximum number of steps = %d\n",gMC->GetMaxNStep());
//
}
//_____________________________________________________________________________
void AliTPCv3::StepManager()
{
//
// Called for every step in the Time Projection Chamber
//
//
// parameters used for the energy loss calculations
//
const Float_t kprim = 14.35; // number of primary collisions per 1 cm
const Float_t kpoti = 20.77e-9; // first ionization potential for Ne/CO2
const Float_t kwIon = 35.97e-9; // energy for the ion-electron pair creation
const Float_t kbig = 1.e10;
Int_t id,copy;
TLorentzVector pos;
Float_t hits[4];
Int_t vol[2];
TClonesArray &lhits = *fHits;
vol[1]=0;
vol[0]=0;
//
gMC->SetMaxStep(kbig);
if(!gMC->IsTrackAlive()) return; // particle has disappeared
Float_t charge = gMC->TrackCharge();
if(TMath::Abs(charge)<=0.) return; // take only charged particles
id=gMC->CurrentVolID(copy);
// Check the sensitive volume
if (id != fIdSens) return;
//
// charged particle is in the sensitive volume
//
if(gMC->TrackStep() > 0) {
Int_t nel = (Int_t)(((gMC->Edep())-kpoti)/kwIon) + 1;
nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV
gMC->TrackPosition(pos);
hits[0]=pos[0];
hits[1]=pos[1];
hits[2]=pos[2];
//
// check the selected side of the TPC
//
if(fSide && fSide*hits[2]<=0.) return;
hits[3]=(Float_t)nel;
// Add this hit
new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
}
// Stemax calculation for the next step
Float_t pp;
TLorentzVector mom;
gMC->TrackMomentum(mom);
Float_t ptot=mom.Rho();
Float_t betaGamma = ptot/gMC->TrackMass();
Int_t pid=gMC->TrackPid();
if((pid==kElectron || pid==kPositron) && ptot > 0.002)
{
pp = kprim*1.58; // electrons above 20 MeV/c are on the plateau!
}
else
{
pp=kprim*BetheBloch(betaGamma);
if(TMath::Abs(charge) > 1.) pp *= (charge*charge);
}
Float_t random[1];
gMC->Rndm(random,1); // good, old GRNDM from Geant3
Double_t rnd = (Double_t)random[0];
gMC->SetMaxStep(-TMath::Log(rnd)/pp);
}
//_____________________________________________________________________________
Float_t AliTPCv3::BetheBloch(Float_t bg)
{
//
// Bethe-Bloch energy loss formula
//
const Double_t kp1=0.76176e-1;
const Double_t kp2=10.632;
const Double_t kp3=0.13279e-4;
const Double_t kp4=1.8631;
const Double_t kp5=1.9479;
Double_t dbg = (Double_t) bg;
Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg);
Double_t aa = TMath::Power(beta,kp4);
Double_t bb = TMath::Power(1./dbg,kp5);
bb=TMath::Log(kp3+bb);
return ((Float_t)((kp2-aa-bb)*kp1/aa));
}