RICH/AliRICH.cxx

   1 //  **************************************************************************
   2 //  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3 //  *                                                                        *
   4 //  * Author: The ALICE Off-line Project.                                    *
   5 //  * Contributors are mentioned in the code where appropriate.              *
   6 //  *                                                                        *
   7 //  * Permission to use, copy, modify and distribute this software and its   *
   8 //  * documentation strictly for non-commercial purposes is hereby granted   *
   9 //  * without fee, provided that the above copyright notice appears in all   *
  10 //  * copies and that both the copyright notice and this permission notice   *
  11 //  * appear in the supporting documentation. The authors make no claims     *
  12 //  * about the suitability of this software for any purpose. It is          *
  13 //  * provided "as is" without express or implied warranty.                  *
  14 //  **************************************************************************
  15
  16 #include "AliRICH.h"
  17 #include "AliRICHParam.h"
  18 #include "AliRICHChamber.h"
  19 #include <TArrayF.h>
  20 #include <TGeometry.h>
  21 #include <TBRIK.h>
  22 #include <TTUBE.h>
  23 #include <TFile.h>
  24 #include <TNode.h>
  25 #include <TObjArray.h>
  26 #include <AliMagF.h>
  27 #include <AliRun.h>
  28 #include <AliRunDigitizer.h>
  29 #include <AliMC.h>
  30 #include <TVirtualMC.h>
  31
  32 ClassImp(AliRICHhit)
  33 //__________________________________________________________________________________________________
  34 void AliRICHhit::Print(Option_t*)const
  35 {
  36   ::Info("hit","chamber=%2i, PID=%9i, TID=%6i, eloss=%8.3f eV",fChamber,fPid,fTrack,fEloss*1e9);
  37 }
  38 //__________________________________________________________________________________________________
  39 ClassImp(AliRICHdigit)
  40 //__________________________________________________________________________________________________
  41 void AliRICHdigit::Print(Option_t*)const
  42 {
  43   ::Info("digit","ID=%6i, PID=%9i, c=%2i, x=%3i, y=%3i, q=%8.2f, TID1=%5i, TID2=%5i, TID3=%5i",
  44            Id(),   fCombiPid,fChamber,fPadX,fPadY,fQdc,fTracks[0],fTracks[1],fTracks[2]);
  45 }
  46 //__________________________________________________________________________________________________
  47 ClassImp(AliRICHcluster)
  48 //__________________________________________________________________________________________________
  49 void AliRICHcluster::Print(Option_t*)const
  50 {
  51   ::Info("cluster","CombiPid=%10i, c=%2i, size=%4i, dim=%5i, x=%7.3f, y=%7.3f, Q=%6i, st=%i",
  52            fCombiPid,fChamber,fSize,fDimXY,fX,fY,fQdc,fStatus);
  53 }
  54 //__________________________________________________________________________________________________
  55 ClassImp(AliRICH)
  56 //__________________________________________________________________________________________________
  57 // RICH manager class
  58 //BEGIN_HTML
  59 /*
  60   <img src="gif/alirich.gif">
  61 */
  62 //END_HTML
  63 //__________________________________________________________________________________________________
  64 AliRICH::AliRICH()
  65         :AliDetector()
  66 {
  67 //Default ctor should not contain any new operators
  68   fpParam     =0;
  69   fChambers   =0;
  70 //AliDetector ctor deals with Hits and Digits
  71   fSdigits    =0; fNsdigits   =0;
  72   fDigitsNew  =0; for(int i=0;i<kNCH;i++) fNdigitsNew[i]  =0;
  73   fClusters   =0; for(int i=0;i<kNCH;i++) fNclusters[i]=0;
  74
  75   fCerenkovs  =0; fNcerenkovs =0;
  76   fSpecials   =0; fNspecials  =0;
  77   fCkovNumber=fFreonProd=0;
  78 }//AliRICH::AliRICH()
  79 //__________________________________________________________________________________________________
  80 AliRICH::AliRICH(const char *name, const char *title)
  81         :AliDetector(name,title)
  82 {
  83 //Named ctor
  84   if(GetDebug())Info("named ctor","Start.");
  85   fpParam     =   new AliRICHParam;
  86   fChambers = 0;  CreateChambers();
  87 //AliDetector ctor deals with Hits and Digits (reset them to 0, does not create them)
  88   fHits=       0;     CreateHits();          gAlice->GetMCApp()->AddHitList(fHits);
  89   fSdigits=    0;
  90   fDigitsNew=  0;
  91   fClusters=   0;
  92
  93   fCerenkovs=  0;     CreateCerenkovsOld();  gAlice->GetMCApp()->AddHitList(fCerenkovs);
  94   fSpecials=   0;     CreateSpecialsOld();
  95
  96   fCkovNumber=fFreonProd=0;
  97   if(GetDebug())Info("named ctor","Stop.");
  98 }//AliRICH::AliRICH(const char *name, const char *title)
  99 //__________________________________________________________________________________________________
 100 AliRICH::~AliRICH()
 101 {
 102 //dtor
 103   if(GetDebug()) Info("dtor","Start.");
 104
 105   if(fpParam)    delete fpParam;
 106   if(fChambers)  delete fChambers;
 107
 108   if(fHits)      delete fHits;
 109   if(fSdigits)   delete fSdigits;
 110   if(fDigits)    delete fDigits;
 111   if(fDigitsNew) {fDigitsNew->Delete();   delete fDigitsNew;}
 112   if(fClusters)  {fClusters->Delete();    delete fClusters;}
 113
 114   if(fCerenkovs) delete fCerenkovs;
 115   if(fSpecials)  delete fSpecials;
 116   if(GetDebug()) Info("dtor","Stop.");
 117 }//AliRICH::~AliRICH()
 118 //__________________________________________________________________________________________________
 119 void AliRICH::Hits2SDigits()
 120 {
 121 //Create a list of sdigits corresponding to list of hits. Every hit generates one or more sdigits.
 122   if(GetDebug()) Info("Hit2SDigits","Start.");
 123   if(GetDebug()) Info("Hit2SDigits","Stop.");
 124 }//void AliRICH::Hits2SDigits()
 125 //__________________________________________________________________________________________________
 126 void AliRICH::SDigits2Digits()
 127 {
 128 //Generate digits from sdigits.
 129   if(GetDebug()) Info("SDigits2Digits","Start.");
 130   if(GetDebug()) Info("SDigits2Digits","Stop.");
 131 }//SDigits2Digits()
 132 //__________________________________________________________________________________________________
 133 void AliRICH::BuildGeometry()
 134 {
 135 //Builds a TNode geometry for event display
 136   if(GetDebug())Info("BuildGeometry","Start.");
 137
 138   TNode *node, *subnode, *top;
 139   top=gAlice->GetGeometry()->GetNode("alice");
 140
 141   new TBRIK("S_RICH","S_RICH","void",71.09999,11.5,73.15);
 142
 143   Float_t wid=Param()->SectorSizeX();
 144   Float_t len=Param()->SectorSizeY();
 145   new TBRIK("PHOTO","PHOTO","void",wid/2,0.1,len/2);
 146
 147   for(int i=1;i<=kNCH;i++){
 148     top->cd();
 149     node = new TNode(Form("RICH%i",i),Form("RICH%i",i),"S_RICH",C(i)->X(),C(i)->Y(),C(i)->Z(),C(i)->RotMatrixName());
 150     node->SetLineColor(kRed);
 151     node->cd();
 152     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",wid+Param()->DeadZone(),5,len/2+Param()->DeadZone()/2,"");
 153     subnode->SetLineColor(kGreen);
 154     fNodes->Add(subnode);
 155     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",0,5,len/2+Param()->DeadZone()/2,"");
 156     subnode->SetLineColor(kGreen);
 157     fNodes->Add(subnode);
 158     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",-wid-Param()->DeadZone(),5,len/2+Param()->DeadZone()/2,"");
 159     subnode->SetLineColor(kGreen);
 160     fNodes->Add(subnode);
 161     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",wid+Param()->DeadZone(),5,-len/2-Param()->DeadZone()/2,"");
 162     subnode->SetLineColor(kGreen);
 163     fNodes->Add(subnode);
 164     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",0,5,-len/2 -Param()->DeadZone()/2,"");
 165     subnode->SetLineColor(kGreen);
 166     fNodes->Add(subnode);
 167     subnode = new TNode("PHOTO1","PHOTO1","PHOTO",-wid-Param()->DeadZone(),5,-len/2 - Param()->DeadZone()/2,"");
 168     subnode->SetLineColor(kGreen);
 169     fNodes->Add(subnode);
 170     fNodes->Add(node);
 171   }
 172   if(GetDebug())Info("BuildGeometry","Stop.");
 173 }//void AliRICH::BuildGeometry()
 174
 175 //______________________________________________________________________________
 176 void AliRICH::CreateMaterials()
 177 {
 178     //
 179     // *** DEFINITION OF AVAILABLE RICH MATERIALS ***
 180     // ORIGIN    : NICK VAN EIJNDHOVEN
 181     // Modified by:  N. Colonna (INFN - BARI, Nicola.Colonna@ba.infn.it)
 182     //               R.A. Fini  (INFN - BARI, Rosanna.Fini@ba.infn.it)
 183     //               R.A. Loconsole (Bari University, loco@riscom.ba.infn.it)
 184     //
 185     Int_t i;
 186
 187     //Photons energy intervals
 188     Float_t ppckov[26];
 189     for (i=0;i<26;i++)
 190     {
 191         ppckov[i] = (Float_t(i)*0.1+5.5)*1e-9;
 192     }
 193
 194
 195     //Refraction index for quarz
 196     Float_t rIndexQuarz[26];
 197     Float_t  e1= 10.666;
 198     Float_t  e2= 18.125;
 199     Float_t  f1= 46.411;
 200     Float_t  f2= 228.71;
 201     for (i=0;i<26;i++)
 202     {
 203         Float_t ene=ppckov[i]*1e9;
 204         Float_t a=f1/(e1*e1 - ene*ene);
 205         Float_t b=f2/(e2*e2 - ene*ene);
 206         rIndexQuarz[i] = TMath::Sqrt(1. + a + b );
 207     }
 208
 209     //Refraction index for opaque quarz, methane and grid
 210     Float_t rIndexOpaqueQuarz[26];
 211     Float_t rIndexMethane[26];
 212     Float_t rIndexGrid[26];
 213     for (i=0;i<26;i++)
 214     {
 215         rIndexOpaqueQuarz[i]=1;
 216         rIndexMethane[i]=1.000444;
 217         rIndexGrid[i]=1;
 218     }
 219
 220     //Absorption index for freon
 221     Float_t abscoFreon[26] = {179.0987, 179.0987, 179.0987, 179.0987, 179.0987,  179.0987, 179.0987, 179.0987,
 222                                179.0987, 142.9206, 56.64957, 25.58622, 13.95293, 12.03905, 10.42953, 8.804196,
 223                                7.069031, 4.461292, 2.028366, 1.293013, .577267,   .40746,  .334964, 0., 0., 0.};
 224
 225
 226     Float_t abscoQuarz [26] = {105.8, 65.52, 48.58, 42.85, 35.79, 31.262, 28.598, 27.527, 25.007, 22.815, 21.004,
 227                                 19.266, 17.525, 15.878, 14.177, 11.719, 9.282, 6.62, 4.0925, 2.601, 1.149, .667, .3627,
 228                                 .192, .1497, .10857};
 229
 230     //Absorption index for methane
 231     Float_t abscoMethane[26];
 232     for (i=0;i<26;i++)
 233     {
 234         abscoMethane[i]=AbsoCH4(ppckov[i]*1e9);
 235     }
 236
 237     //Absorption index for opaque quarz, csi and grid, efficiency for all and grid
 238     Float_t abscoOpaqueQuarz[26];
 239     Float_t abscoCsI[26];
 240     Float_t abscoGrid[26];
 241     Float_t efficAll[26];
 242     Float_t efficGrid[26];
 243     for (i=0;i<26;i++)
 244     {
 245         abscoOpaqueQuarz[i]=1e-5;
 246         abscoCsI[i]=1e-4;
 247         abscoGrid[i]=1e-4;
 248         efficAll[i]=1;
 249         efficGrid[i]=1;
 250     }
 251
 252     //Efficiency for csi
 253
 254     Float_t efficCsI[26] = {0.000199999995, 0.000600000028, 0.000699999975, 0.00499999989, 0.00749999983, 0.010125,
 255                              0.0242999997, 0.0405000001, 0.0688500032, 0.105299994, 0.121500008, 0.141749993, 0.157949999,
 256                              0.162, 0.166050002, 0.167669997, 0.174299985, 0.176789999, 0.179279998, 0.182599992, 0.18592,
 257                              0.187579989, 0.189239994, 0.190899998, 0.207499996, 0.215799987};
 258
 259
 260
 261     //FRESNEL LOSS CORRECTION FOR PERPENDICULAR INCIDENCE AND
 262     //UNPOLARIZED PHOTONS
 263
 264     for (i=0;i<26;i++)
 265     {
 266         efficCsI[i] = efficCsI[i]/(1.-Fresnel(ppckov[i]*1e9,1.,0));
 267     }
 268
 269     /*******************************************End of rich_media.f***************************************/
 270
 271   Float_t rIndexFreon[26];
 272
 273
 274     // --- Photon energy (GeV)
 275     // --- Refraction indexes
 276     for (i = 0; i < 26; ++i) {
 277       rIndexFreon[i] = ppckov[i] * .0172 * 1e9 + 1.177;
 278       //rIndexFreon[i] = 1;
 279     }
 280
 281
 282   Float_t a=0,z=0,den=0,radl=0,absl=0;
 283   Float_t tmaxfd=-10.0, deemax=-0.2, stemax=-0.1,epsil=0.001, stmin=-0.001;
 284   Int_t   isxfld = gAlice->Field()->Integ();
 285   Float_t sxmgmx = gAlice->Field()->Max();
 286
 287   AliMaterial( 1, "Air     $",a=14.61,z=7.3, den=0.001205,radl=30420.0,absl=67500);//(Air)
 288   AliMedium(1, "DEFAULT MEDIUM AIR$", 1, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 289
 290   AliMaterial( 6, "HON",      a=12.01,z=6.0, den=0.1,     radl=18.8,   absl=0);    //(C)-equivalent radl
 291   AliMedium(2, "HONEYCOMB$", 6, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 292
 293   AliMaterial(16, "CSI",      a=12.01,z=6.0, den=0.1,     radl=18.8,   absl=0);    //CsI-radl equivalent
 294   AliMedium(kCSI, "CSI$", 16, 1, isxfld, sxmgmx,tmaxfd, stemax, deemax, epsil, stmin);
 295
 296   AliMaterial(11, "GRI",      a=63.54,z=29.0,den=8.96,    radl=1.43,   absl=0);    //anode grid (Cu)
 297   AliMedium(7, "GRIGLIA$", 11, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 298
 299   AliMaterial(50, "ALUM",     a=26.98,z=13.0,den=2.7,     radl=8.9,    absl=0);    //aluminium sheet (Al)
 300   AliMedium(10, "ALUMINUM$", 50, 1, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 301
 302   AliMaterial(31, "COPPER$",  a=63.54,z=29.0,den=8.96,    radl=1.4,    absl=0);    //(Cu)
 303   AliMedium(12, "PCB_COPPER", 31, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 304
 305   Float_t  aQuartz[2]={28.09,16.0};  Float_t  zQuartz[2]={14.00, 8.0};  Float_t  wmatQuartz[2]={1,2};
 306   AliMixture (20, "QUA",aQuartz,zQuartz,den=2.64,-2, wmatQuartz);//Quarz (SiO2) - trasnparent
 307   AliMedium(3, "QUARZO$", 20, 1, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 308
 309   AliMixture (21, "QUAO",aQuartz, zQuartz, den=2.64, -2, wmatQuartz);//Quarz (SiO2) - opaque
 310   AliMedium(8, "QUARZOO$", 21, 1, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 311
 312   Float_t  aFreon[2]={12,19};  Float_t  zFreon[2]={6,9};  Float_t wmatFreon[2]={6,14};
 313   AliMixture (30, "FRE",aFreon,zFreon,den=1.7,-2,wmatFreon);//Freon (C6F14)
 314   AliMedium(4, "FREON$", 30, 1, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 315
 316   Float_t aMethane[2]={12.01,1}; Float_t zMethane[2]={6,1}; Float_t wmatMethane[2]={1,4};
 317   AliMixture (40, "MET", aMethane, zMethane, den=7.17e-4,-2, wmatMethane);//methane (CH4)
 318   AliMedium(5, "METANO$", 40, 1, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 319
 320   AliMixture (41, "METG", aMethane, zMethane, den=7.17e-4, -2, wmatMethane);
 321   AliMedium(kGAP, "GAP$", 41, 1, isxfld, sxmgmx,tmaxfd, 0.1, -deemax, epsil, -stmin);
 322
 323   Float_t aGlass[5]={12.01, 28.09, 16.,   10.8,  23.};
 324   Float_t zGlass[5]={ 6.,   14.,    8.,    5.,   11.};
 325   Float_t wGlass[5]={ 0.5,  0.105, 0.355, 0.03,  0.01};
 326   AliMixture (32, "GLASS",aGlass, zGlass, den=1.74, 5, wGlass);//Glass 50%C+10.5%Si+35.5%O+3% + 1%
 327   AliMedium(11, "GLASS", 32, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
 328
 329   Int_t *idtmed = fIdtmed->GetArray()-999;
 330   gMC->SetCerenkov(idtmed[1000], 26, ppckov, abscoMethane,     efficAll,  rIndexMethane);
 331   gMC->SetCerenkov(idtmed[1001], 26, ppckov, abscoMethane,     efficAll,  rIndexMethane);
 332   gMC->SetCerenkov(idtmed[1002], 26, ppckov, abscoQuarz,       efficAll,  rIndexQuarz);
 333   gMC->SetCerenkov(idtmed[1003], 26, ppckov, abscoFreon,       efficAll,  rIndexFreon);
 334   gMC->SetCerenkov(idtmed[1004], 26, ppckov, abscoMethane,     efficAll,  rIndexMethane);
 335   gMC->SetCerenkov(idtmed[1005], 26, ppckov, abscoCsI,         efficCsI,  rIndexMethane);
 336   gMC->SetCerenkov(idtmed[1006], 26, ppckov, abscoGrid,        efficGrid, rIndexGrid);
 337   gMC->SetCerenkov(idtmed[1007], 26, ppckov, abscoOpaqueQuarz, efficAll,  rIndexOpaqueQuarz);
 338   gMC->SetCerenkov(idtmed[1008], 26, ppckov, abscoMethane,     efficAll,  rIndexMethane);
 339   gMC->SetCerenkov(idtmed[1009], 26, ppckov, abscoGrid,        efficGrid, rIndexGrid);
 340   gMC->SetCerenkov(idtmed[1010], 26, ppckov, abscoOpaqueQuarz, efficAll,  rIndexOpaqueQuarz);
 341 }//void AliRICH::CreateMaterials()
 342 //__________________________________________________________________________________________________
 343 Float_t AliRICH::Fresnel(Float_t ene,Float_t pdoti, Bool_t pola)const
 344 {
 345
 346     //ENE(EV), PDOTI=COS(INC.ANG.), PDOTR=COS(POL.PLANE ROT.ANG.)
 347
 348     Float_t en[36] = {5.0,5.1,5.2,5.3,5.4,5.5,5.6,5.7,5.8,5.9,6.0,6.1,6.2,
 349                       6.3,6.4,6.5,6.6,6.7,6.8,6.9,7.0,7.1,7.2,7.3,7.4,7.5,7.6,7.7,
 350                       7.8,7.9,8.0,8.1,8.2,8.3,8.4,8.5};
 351     Float_t csin[36] = {2.14,2.21,2.33,2.48,2.76,2.97,2.99,2.59,2.81,3.05,
 352                         2.86,2.53,2.55,2.66,2.79,2.96,3.18,3.05,2.84,2.81,2.38,2.11,
 353                         2.01,2.13,2.39,2.73,3.08,3.15,2.95,2.73,2.56,2.41,2.12,1.95,
 354                         1.72,1.53};
 355     Float_t csik[36] = {0.,0.,0.,0.,0.,0.196,0.408,0.208,0.118,0.49,0.784,0.543,
 356                         0.424,0.404,0.371,0.514,0.922,1.102,1.139,1.376,1.461,1.253,0.878,
 357                         0.69,0.612,0.649,0.824,1.347,1.571,1.678,1.763,1.857,1.824,1.824,
 358                         1.714,1.498};
 359     Float_t xe=ene;
 360     Int_t  j=Int_t(xe*10)-49;
 361     Float_t cn=csin[j]+((csin[j+1]-csin[j])/0.1)*(xe-en[j]);
 362     Float_t ck=csik[j]+((csik[j+1]-csik[j])/0.1)*(xe-en[j]);
 363
 364     //FORMULAE FROM HANDBOOK OF OPTICS, 33.23 OR
 365     //W.R. HUNTER, J.O.S.A. 54 (1964),15 , J.O.S.A. 55(1965),1197
 366
 367     Float_t sinin=TMath::Sqrt(1-pdoti*pdoti);
 368     Float_t tanin=sinin/pdoti;
 369
 370     Float_t c1=cn*cn-ck*ck-sinin*sinin;
 371     Float_t c2=4*cn*cn*ck*ck;
 372     Float_t aO=TMath::Sqrt(0.5*(TMath::Sqrt(c1*c1+c2)+c1));
 373     Float_t b2=0.5*(TMath::Sqrt(c1*c1+c2)-c1);
 374
 375     Float_t rs=((aO-pdoti)*(aO-pdoti)+b2)/((aO+pdoti)*(aO+pdoti)+b2);
 376     Float_t rp=rs*((aO-sinin*tanin)*(aO-sinin*tanin)+b2)/((aO+sinin*tanin)*(aO+sinin*tanin)+b2);
 377
 378
 379     //CORRECTION FACTOR FOR SURFACE ROUGHNESS
 380     //B.J. STAGG  APPLIED OPTICS, 30(1991),4113
 381
 382     Float_t sigraf=18.;
 383     Float_t lamb=1240/ene;
 384     Float_t fresn;
 385
 386     Float_t  rO=TMath::Exp(-(4*TMath::Pi()*pdoti*sigraf/lamb)*(4*TMath::Pi()*pdoti*sigraf/lamb));
 387
 388     if(pola)
 389     {
 390         Float_t pdotr=0.8;                                 //DEGREE OF POLARIZATION : 1->P , -1->S
 391         fresn=0.5*(rp*(1+pdotr)+rs*(1-pdotr));
 392     }
 393     else
 394         fresn=0.5*(rp+rs);
 395
 396     fresn = fresn*rO;
 397     return(fresn);
 398 }//Fresnel()
 399 //__________________________________________________________________________________________________
 400 Float_t AliRICH::AbsoCH4(Float_t x)const
 401 {
 402 //Evaluate the absorbtion lenght of CH4
 403   Float_t sch4[9] = {.12,.16,.23,.38,.86,2.8,7.9,28.,80.};              //MB X 10^22
 404   Float_t em[9] = {8.1,8.158,8.212,8.267,8.322,8.378,8.435,8.493,8.55};
 405   const Float_t kLoschmidt=2.686763e19;                                      // LOSCHMIDT NUMBER IN CM-3
 406   const Float_t kPressure=750.,kTemperature=283.;
 407   const Float_t kPn=kPressure/760.;
 408   const Float_t kTn=kTemperature/273.16;
 409   const Float_t kC0=-1.655279e-1;
 410   const Float_t kC1=6.307392e-2;
 411   const Float_t kC2=-8.011441e-3;
 412   const Float_t kC3=3.392126e-4;
 413
 414   Float_t crossSection=0;
 415   if (x<7.75)
 416     crossSection=.06e-22;
 417   else if(x>=7.75 && x<=8.1){                 //------ METHANE CROSS SECTION cm-2 ASTROPH. J. 214, L47 (1978)
 418         crossSection=(kC0+kC1*x+kC2*x*x+kC3*x*x*x)*1.e-18;
 419   }else if (x> 8.1){
 420     Int_t j=0;
 421     while (x<=em[j] || x>=em[j+1]){
 422       j++;
 423       Float_t a=(sch4[j+1]-sch4[j])/(em[j+1]-em[j]);
 424       crossSection=(sch4[j]+a*(x-em[j]))*1e-22;
 425     }
 426   }//if
 427
 428     Float_t density=kLoschmidt*kPn/kTn; //CH4 molecular density 1/cm-3
 429     return 1./(density*crossSection);
 430 }//AbsoCH4()
 431 //__________________________________________________________________________________________________
 432 void AliRICH::MakeBranch(Option_t* option)
 433 {
 434 //Create Tree branches for the RICH.
 435   if(GetDebug())Info("MakeBranch","Start with option= %s.",option);
 436
 437   const Int_t kBufferSize = 4000;
 438
 439   const char *cH = strstr(option,"H");
 440   const char *cD = strstr(option,"D");
 441   const char *cR = strstr(option,"R");
 442   const char *cS = strstr(option,"S");
 443
 444   if(cH&&TreeH()){//H
 445     CreateHits();      //branch will be created in AliDetector::MakeBranch
 446     CreateCerenkovsOld(); MakeBranchInTree(TreeH(),"RICHCerenkov", &fCerenkovs, kBufferSize,0);
 447     CreateSpecialsOld();  MakeBranchInTree(TreeH(),"RICHSpecials", &fSpecials,kBufferSize,0);
 448   }//H
 449   AliDetector::MakeBranch(option);//this is after cH because we need to guarantee that fHits array is created
 450
 451   if(cS&&fLoader->TreeS()){//S
 452     CreateSDigits();   MakeBranchInTree(fLoader->TreeS(),"RICH",&fSdigits,kBufferSize,0) ;
 453   }//S
 454
 455   if(cD&&fLoader->TreeD()){//D
 456     CreateDigits();
 457     for(Int_t i=0;i<kNCH;i++){
 458       MakeBranchInTree(fLoader->TreeD(),Form("%s%d",GetName(),i+1),&((*fDigitsNew)[i]),kBufferSize,0);
 459     }
 460   }//D
 461
 462   if(cR&&fLoader->TreeR()){//R
 463     CreateClusters();
 464     for(Int_t i=0;i<kNCH;i++)
 465       MakeBranchInTree(fLoader->TreeR(),Form("%sClusters%d",GetName(),i+1), &((*fClusters)[i]), kBufferSize, 0);
 466   }//R
 467   if(GetDebug())Info("MakeBranch","Stop.");
 468 }//void AliRICH::MakeBranch(Option_t* option)
 469 //__________________________________________________________________________________________________
 470 void AliRICH::SetTreeAddress()
 471 {
 472 //Set branch address for the Hits and Digits Tree.
 473   if(GetDebug())Info("SetTreeAddress","Start.");
 474
 475   TBranch *branch;
 476
 477   if(fLoader->TreeH()){//H
 478     if(GetDebug())Info("SetTreeAddress","tree H is requested.");
 479     CreateHits();//branch map will be in AliDetector::SetTreeAddress
 480     branch=fLoader->TreeH()->GetBranch("RICHCerenkov");   if(branch){CreateCerenkovsOld(); branch->SetAddress(&fCerenkovs);}
 481     branch=fLoader->TreeH()->GetBranch("RICHSpecials");   if(branch){CreateSpecialsOld();  branch->SetAddress(&fSpecials);}
 482   }//H
 483   AliDetector::SetTreeAddress();//this is after TreeH because we need to guarantee that fHits array is created
 484
 485   if(fLoader->TreeS()){//S
 486     if(GetDebug())Info("SetTreeAddress","tree S is requested.");
 487     branch=fLoader->TreeS()->GetBranch(GetName());        if(branch){CreateSDigits();   branch->SetAddress(&fSdigits);}
 488   }//S
 489
 490   if(fLoader->TreeD()){//D
 491     if(GetDebug())Info("SetTreeAddress","tree D is requested.");
 492     for(int i=0;i<kNCH;i++){
 493       branch=fLoader->TreeD()->GetBranch(Form("%s%d",GetName(),i+1));
 494       if(branch){CreateDigits(); branch->SetAddress(&((*fDigitsNew)[i]));}
 495     }
 496   }//D
 497
 498   if(fLoader->TreeR()){//R
 499     if(GetDebug())Info("SetTreeAddress","tree R is requested.");
 500     for(int i=0;i<kNCH;i++){
 501       branch=fLoader->TreeR()->GetBranch(Form("%sClusters%d" ,GetName(),i+1));
 502       if(branch){CreateClusters(); branch->SetAddress(&((*fClusters)[i]));}
 503     }
 504   }//R
 505   if(GetDebug())Info("SetTreeAddress","Stop.");
 506 }//void AliRICH::SetTreeAddress()
 507 //__________________________________________________________________________________________________
 508 void AliRICH::Print(Option_t *option)const
 509 {
 510 //Debug printout
 511   TObject::Print(option);
 512   Param()->Dump();
 513   fChambers->Print(option);
 514 }//void AliRICH::Print(Option_t *option)const
 515 //__________________________________________________________________________________________________
 516 void AliRICH::CreateGeometry()
 517 {
 518 //Creates detailed geometry simulation (currently GEANT volumes tree)
 519   if(GetDebug())Info("CreateGeometry","Start.");
 520 //Opaque quartz thickness
 521   Float_t oquaThickness = .5;
 522 //CsI dimensions
 523   Float_t pcX=Param()->PcSizeX();
 524   Float_t pcY=Param()->PcSizeY();
 525
 526   Int_t *idtmed = fIdtmed->GetArray()-999;
 527
 528   Int_t i;
 529   Float_t zs;
 530   Int_t idrotm[1099];
 531   Float_t par[3];
 532
 533 //External aluminium box
 534   par[0]=68.8;par[1]=13;par[2]=70.86;  gMC->Gsvolu("RICH", "BOX ", idtmed[1009], par, 3);
 535 //Air
 536   par[0]=66.3;   par[1] = 13; par[2] = 68.35;      gMC->Gsvolu("SRIC", "BOX ", idtmed[1000], par, 3);
 537 //Air 2 (cutting the lower part of the box)
 538   par[0]=1.25;    par[1] = 3;    par[2] = 70.86;   gMC->Gsvolu("AIR2", "BOX ", idtmed[1000], par, 3);
 539 //Air 3 (cutting the lower part of the box)
 540   par[0]=66.3;    par[1] = 3;  par[2] = 1.2505;    gMC->Gsvolu("AIR3", "BOX ", idtmed[1000], par, 3);
 541 //Honeycomb
 542   par[0]=66.3;par[1]=0.188;  par[2] = 68.35;       gMC->Gsvolu("HONE", "BOX ", idtmed[1001], par, 3);
 543 //Aluminium sheet
 544   par[0]=66.3;par[1]=0.025;par[2]=68.35;           gMC->Gsvolu("ALUM", "BOX ", idtmed[1009], par, 3);
 545   //par[0] = 66.5; par[1] = .025; par[2] = 63.1;
 546 //Quartz
 547   par[0]=Param()->QuartzWidth()/2;par[1]=Param()->QuartzThickness()/2;par[2]=Param()->QuartzLength()/2;
 548   gMC->Gsvolu("QUAR", "BOX ", idtmed[1002], par, 3);
 549 //Spacers (cylinders)
 550   par[0]=0.;par[1]=.5;par[2]=Param()->FreonThickness()/2;  gMC->Gsvolu("SPAC", "TUBE", idtmed[1002], par, 3);
 551 //Feet (freon slabs supports)
 552   par[0] = .7;  par[1] = .3;  par[2] = 1.9;        gMC->Gsvolu("FOOT", "BOX", idtmed[1009], par, 3);
 553 //Opaque quartz
 554   par[0]=Param()->QuartzWidth()/2;par[1]= .2;par[2]=Param()->QuartzLength()/2;
 555   gMC->Gsvolu("OQUA", "BOX ", idtmed[1007], par, 3);
 556 //Frame of opaque quartz
 557   par[0]=Param()->OuterFreonWidth()/2;par[1]=Param()->FreonThickness()/2;par[2]=Param()->OuterFreonLength()/2;
 558   gMC->Gsvolu("OQF1", "BOX ", idtmed[1007], par, 3);
 559   par[0]=Param()->InnerFreonWidth()/2;par[1]=Param()->FreonThickness()/2;par[2]=Param()->InnerFreonLength()/2;
 560   gMC->Gsvolu("OQF2", "BOX ", idtmed[1007], par, 3);
 561 //Freon
 562   par[0]=Param()->OuterFreonWidth()/2 - oquaThickness;
 563   par[1]=Param()->FreonThickness()/2;
 564   par[2]=Param()->OuterFreonLength()/2 - 2*oquaThickness;
 565   gMC->Gsvolu("FRE1", "BOX ", idtmed[1003], par, 3);
 566
 567   par[0]=Param()->InnerFreonWidth()/2 - oquaThickness;
 568   par[1]=Param()->FreonThickness()/2;
 569   par[2]=Param()->InnerFreonLength()/2 - 2*oquaThickness;
 570   gMC->Gsvolu("FRE2", "BOX ", idtmed[1003], par, 3);
 571 //Methane
 572   par[0]=pcX/2;par[1]=Param()->GapThickness()/2;par[2]=pcY/2;         gMC->Gsvolu("META","BOX ",idtmed[1004], par, 3);
 573 //Methane gap
 574   par[0]=pcX/2;par[1]=Param()->ProximityGapThickness()/2;par[2]=pcY/2;gMC->Gsvolu("GAP ","BOX ",(*fIdtmed)[kGAP],par,3);
 575 //CsI PC
 576   par[0]=pcX/2;par[1]=.25;par[2]=pcY/2;  gMC->Gsvolu("CSI ", "BOX ", (*fIdtmed)[kCSI], par, 3);
 577 //Anode grid
 578   par[0] = 0.;par[1] = .001;par[2] = 20.;  gMC->Gsvolu("GRID", "TUBE", idtmed[1006], par, 3);
 579
 580 //Wire supports
 581 //Bar of metal
 582   par[0]=pcX/2;par[1]=1.05;par[2]=1.05;  gMC->Gsvolu("WSMe", "BOX ", idtmed[1009], par, 3);
 583 //Ceramic pick up (base)
 584   par[0]=pcX/2;par[1]= .25;par[2]=1.05;  gMC->Gsvolu("WSG1", "BOX ", idtmed[1010], par, 3);
 585 //Ceramic pick up (head)
 586   par[0] = pcX/2;par[1] = .1;par[2] = .1;  gMC->Gsvolu("WSG2", "BOX ", idtmed[1010], par, 3);
 587
 588 //Aluminium supports for methane and CsI
 589 //Short bar
 590   par[0]=pcX/2;par[1]=Param()->GapThickness()/2 + .25; par[2] = (68.35 - pcY/2)/2;
 591   gMC->Gsvolu("SMSH", "BOX", idtmed[1009], par, 3);
 592 //Long bar
 593   par[0]=(66.3 - pcX/2)/2;par[1]=Param()->GapThickness()/2+.25;par[2]=pcY/2+68.35-pcY/2;
 594   gMC->Gsvolu("SMLG", "BOX", idtmed[1009], par, 3);
 595
 596 //Aluminium supports for freon
 597 //Short bar
 598   par[0] = Param()->QuartzWidth()/2; par[1] = .3; par[2] = (68.35 - Param()->QuartzLength()/2)/2;
 599   gMC->Gsvolu("SFSH", "BOX", idtmed[1009], par, 3);
 600 //Long bar
 601   par[0] = (66.3 - Param()->QuartzWidth()/2)/2; par[1] = .3;
 602   par[2] = Param()->QuartzLength()/2 + 68.35 - Param()->QuartzLength()/2;
 603   gMC->Gsvolu("SFLG", "BOX", idtmed[1009], par, 3);
 604 //PCB backplane
 605   par[0] = pcX/2;par[1] = .25; par[2] = pcY/4 -.5025;  gMC->Gsvolu("PCB ", "BOX", idtmed[1011], par, 3);
 606
 607 //Backplane supports
 608 //Aluminium slab
 609   par[0] = 33.15;par[1] = 2;par[2] = 21.65;  gMC->Gsvolu("BACK", "BOX", idtmed[1009], par, 3);
 610 //Big hole
 611   par[0] = 9.05; par[1] = 2; par[2] = 4.4625;  gMC->Gsvolu("BKHL", "BOX", idtmed[1000], par, 3);
 612 //Small hole
 613   par[0] = 5.7;par[1] = 2;par[2] = 4.4625;  gMC->Gsvolu("BKHS", "BOX", idtmed[1000], par, 3);
 614 //Place holes inside backplane support
 615   gMC->Gspos("BKHS", 1, "BACK", .8 + 5.7,0., .6 + 4.4625, 0, "ONLY");
 616   gMC->Gspos("BKHS", 2, "BACK", -.8 - 5.7,0., .6 + 4.4625, 0, "ONLY");
 617   gMC->Gspos("BKHS", 3, "BACK", .8 + 5.7,0., -.6 - 4.4625, 0, "ONLY");
 618   gMC->Gspos("BKHS", 4, "BACK", -.8 - 5.7,0., -.6 - 4.4625, 0, "ONLY");
 619   gMC->Gspos("BKHS", 5, "BACK", .8 + 5.7,0., .6 + 8.925 + 1.2 + 4.4625, 0, "ONLY");
 620   gMC->Gspos("BKHS", 6, "BACK", -.8 - 5.7,0., .6 + 8.925 + 1.2 + 4.4625, 0, "ONLY");
 621   gMC->Gspos("BKHS", 7, "BACK", .8 + 5.7,0., -.6 - 8.925 - 1.2 - 4.4625, 0, "ONLY");
 622   gMC->Gspos("BKHS", 8, "BACK", -.8 - 5.7,0., -.6 - 8.925 - 1.2 - 4.4625, 0, "ONLY");
 623   gMC->Gspos("BKHL", 1, "BACK", .8 + 11.4 + 1.6 + 9.05, 0., .6 + 4.4625, 0, "ONLY");
 624   gMC->Gspos("BKHL", 2, "BACK", -.8 - 11.4 - 1.6 - 9.05, 0., .6 + 4.4625, 0, "ONLY");
 625   gMC->Gspos("BKHL", 3, "BACK", .8 + 11.4 + 1.6 + 9.05, 0., -.6 - 4.4625, 0, "ONLY");
 626   gMC->Gspos("BKHL", 4, "BACK", -.8 - 11.4 - 1.6 - 9.05, 0., -.6 - 4.4625, 0, "ONLY");
 627   gMC->Gspos("BKHL", 5, "BACK", .8 + 11.4+ 1.6 + 9.05, 0., .6 + 8.925 + 1.2 + 4.4625, 0, "ONLY");
 628   gMC->Gspos("BKHL", 6, "BACK", -.8 - 11.4 - 1.6 - 9.05, 0., .6 + 8.925 + 1.2 + 4.4625, 0, "ONLY");
 629   gMC->Gspos("BKHL", 7, "BACK", .8 + 11.4 + 1.6 + 9.05, 0., -.6 - 8.925 - 1.2 - 4.4625, 0, "ONLY");
 630   gMC->Gspos("BKHL", 8, "BACK", -.8 - 11.4 - 1.6 - 9.05, 0., -.6 - 8.925 - 1.2 - 4.4625, 0, "ONLY");
 631 //Place material inside RICH
 632   gMC->Gspos("SRIC", 1, "RICH", 0.,0., 0., 0, "ONLY");
 633   gMC->Gspos("AIR2", 1, "RICH", 66.3 + 1.2505, 1.276-Param()->GapThickness()/2-Param()->QuartzThickness()-Param()->FreonThickness()- .4 - .6 - .05 - .376 -.5 - 3.35, 0., 0, "ONLY");
 634   gMC->Gspos("AIR2", 2, "RICH", -66.3 - 1.2505,1.276-Param()->GapThickness()/2-Param()->QuartzThickness()-Param()->FreonThickness()- .4 - .6 - .05 - .376 -.5 - 3.35, 0., 0, "ONLY");
 635   gMC->Gspos("AIR3", 1, "RICH", 0., 1.276-Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .6 - .05 - .376 -.5 - 3.35, -68.35 - 1.25, 0, "ONLY");
 636   gMC->Gspos("AIR3", 2, "RICH", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .6 - .05 - .376 -.5 - 3.35,  68.35 + 1.25, 0, "ONLY");
 637   gMC->Gspos("ALUM", 1, "SRIC", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .6 - .05 - .376 -.025, 0., 0, "ONLY");
 638   gMC->Gspos("HONE", 1, "SRIC", 0., 1.276- Param()->GapThickness()/2  - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .6 - .05 - .188, 0., 0, "ONLY");
 639   gMC->Gspos("ALUM", 2, "SRIC", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .6 - .025, 0., 0, "ONLY");
 640   gMC->Gspos("FOOT", 1, "SRIC", 64.95, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, 36.9, 0, "ONLY");
 641   gMC->Gspos("FOOT", 2, "SRIC", 21.65, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3 , 36.9, 0, "ONLY");
 642   gMC->Gspos("FOOT", 3, "SRIC", -21.65, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, 36.9, 0, "ONLY");
 643   gMC->Gspos("FOOT", 4, "SRIC", -64.95, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, 36.9, 0, "ONLY");
 644   gMC->Gspos("FOOT", 5, "SRIC", 64.95, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, -36.9, 0, "ONLY");
 645   gMC->Gspos("FOOT", 6, "SRIC", 21.65, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, -36.9, 0, "ONLY");
 646   gMC->Gspos("FOOT", 7, "SRIC", -21.65, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, -36.9, 0, "ONLY");
 647   gMC->Gspos("FOOT", 8, "SRIC", -64.95, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .4 - .3, -36.9, 0, "ONLY");
 648   gMC->Gspos("OQUA", 1, "SRIC", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()- .2, 0., 0, "ONLY");
 649 // Methane supports
 650   gMC->Gspos("SMLG", 1, "SRIC", pcX/2 + (66.3 - pcX/2)/2, 1.276 + .25, 0., 0, "ONLY");
 651   gMC->Gspos("SMLG", 2, "SRIC", - pcX/2 - (66.3 - pcX/2)/2, 1.276 + .25, 0., 0, "ONLY");
 652   gMC->Gspos("SMSH", 1, "SRIC", 0., 1.276 + .25, pcY/2 + (68.35 - pcY/2)/2, 0, "ONLY");
 653   gMC->Gspos("SMSH", 2, "SRIC", 0., 1.276 + .25, - pcY/2 - (68.35 - pcY/2)/2, 0, "ONLY");
 654 //Freon supports
 655   Float_t suppY = 1.276 - Param()->GapThickness()/2- Param()->QuartzThickness() -Param()->FreonThickness() - .2 + .3; //y position of freon supports
 656   gMC->Gspos("SFLG", 1, "SRIC", Param()->QuartzWidth()/2 + (66.3 - Param()->QuartzWidth()/2)/2, suppY, 0., 0, "ONLY");
 657   gMC->Gspos("SFLG", 2, "SRIC", - Param()->QuartzWidth()/2 - (66.3 - Param()->QuartzWidth()/2)/2, suppY, 0., 0, "ONLY");
 658   gMC->Gspos("SFSH", 1, "SRIC", 0., suppY, Param()->QuartzLength()/2 + (68.35 - Param()->QuartzLength()/2)/2, 0, "ONLY");
 659   gMC->Gspos("SFSH", 2, "SRIC", 0., suppY, - Param()->QuartzLength()/2 - (68.35 - Param()->QuartzLength()/2)/2, 0, "ONLY");
 660   AliMatrix(idrotm[1019], 0., 0., 90., 0., 90., 90.);
 661 //Place spacers
 662   Int_t nspacers = 30;
 663   for (i = 0; i < nspacers/3; i++) {
 664     zs = -11.6/2 + (TMath::Abs(nspacers/6) - i) * 12.2;
 665     gMC->Gspos("SPAC", i, "FRE1", 10.5, 0., zs, idrotm[1019], "ONLY");  //Original settings
 666   }
 667   for (i = nspacers/3; i < (nspacers*2)/3; i++) {
 668     zs = -11.6/2 + (nspacers/3 + TMath::Abs(nspacers/6) - i) * 12.2;
 669     gMC->Gspos("SPAC", i, "FRE1", 0, 0., zs, idrotm[1019], "ONLY");  //Original settings
 670   }
 671   for (i = (nspacers*2)/3; i < nspacers; ++i) {
 672     zs = -11.6/2 + ((nspacers*2)/3 + TMath::Abs(nspacers/6) - i) * 12.2;
 673     gMC->Gspos("SPAC", i, "FRE1", -10.5, 0., zs, idrotm[1019], "ONLY"); //Original settings
 674   }
 675   for (i = 0; i < nspacers/3; i++) {
 676     zs = -11.6/2 + (TMath::Abs(nspacers/6) - i) * 12.2;
 677     gMC->Gspos("SPAC", i, "FRE2", 10.5, 0., zs, idrotm[1019], "ONLY");  //Original settings
 678   }
 679   for (i = nspacers/3; i < (nspacers*2)/3; i++) {
 680     zs = -11.6/2 + (nspacers/3 + TMath::Abs(nspacers/6) - i) * 12.2;
 681     gMC->Gspos("SPAC", i, "FRE2", 0, 0., zs, idrotm[1019], "ONLY");  //Original settings
 682   }
 683   for (i = (nspacers*2)/3; i < nspacers; ++i) {
 684     zs = -11.6/2 + ((nspacers*2)/3 + TMath::Abs(nspacers/6) - i) * 12.2;
 685     gMC->Gspos("SPAC", i, "FRE2", -10.5, 0., zs, idrotm[1019], "ONLY"); //Original settings
 686   }
 687   gMC->Gspos("FRE1", 1, "OQF1", 0., 0., 0., 0, "ONLY");
 688   gMC->Gspos("FRE2", 1, "OQF2", 0., 0., 0., 0, "ONLY");
 689   gMC->Gspos("OQF1", 1, "SRIC", Param()->OuterFreonWidth()/2 + Param()->InnerFreonWidth()/2 + 2, 1.276 - Param()->GapThickness()/2- Param()->QuartzThickness() -Param()->FreonThickness()/2, 0., 0, "ONLY"); //Original settings (31.3)
 690   gMC->Gspos("OQF2", 2, "SRIC", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()/2, 0., 0, "ONLY");          //Original settings
 691   gMC->Gspos("OQF1", 3, "SRIC", - (Param()->OuterFreonWidth()/2 + Param()->InnerFreonWidth()/2) - 2, 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness() - Param()->FreonThickness()/2, 0., 0, "ONLY");       //Original settings (-31.3)
 692   gMC->Gspos("QUAR", 1, "SRIC", 0., 1.276 - Param()->GapThickness()/2 - Param()->QuartzThickness()/2, 0., 0, "ONLY");
 693   gMC->Gspos("GAP ", 1, "META", 0., Param()->GapThickness()/2 - Param()->ProximityGapThickness()/2 - 0.0001, 0., 0, "ONLY");
 694   gMC->Gspos("META", 1, "SRIC", 0., 1.276, 0., 0, "ONLY");
 695   gMC->Gspos("CSI ", 1, "SRIC", 0., 1.276 + Param()->GapThickness()/2 + .25, 0., 0, "ONLY");
 696 //Wire support placing
 697   gMC->Gspos("WSG2", 1, "GAP ", 0., Param()->ProximityGapThickness()/2 - .1, 0., 0, "ONLY");
 698   gMC->Gspos("WSG1", 1, "CSI ", 0., 0., 0., 0, "ONLY");
 699   gMC->Gspos("WSMe", 1, "SRIC ", 0., 1.276 + Param()->GapThickness()/2 + .5 + 1.05, 0., 0, "ONLY");
 700 //Backplane placing
 701   gMC->Gspos("BACK", 1, "SRIC ", -33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2, 43.3, 0, "ONLY");
 702   gMC->Gspos("BACK", 2, "SRIC ", 33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2 , 43.3, 0, "ONLY");
 703   gMC->Gspos("BACK", 3, "SRIC ", -33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2, 0., 0, "ONLY");
 704   gMC->Gspos("BACK", 4, "SRIC ", 33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2, 0., 0, "ONLY");
 705   gMC->Gspos("BACK", 5, "SRIC ", 33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2, -43.3, 0, "ONLY");
 706   gMC->Gspos("BACK", 6, "SRIC ", -33.15, 1.276 + Param()->GapThickness()/2 + .5 + 2.1 + 2, -43.3, 0, "ONLY");
 707 //PCB placing
 708   gMC->Gspos("PCB ", 1, "SRIC ", 0.,  1.276 + Param()->GapThickness()/2 + .5 + 1.05, pcX/4 + .5025 + 2.5, 0, "ONLY");
 709   gMC->Gspos("PCB ", 2, "SRIC ", 0.,  1.276 + Param()->GapThickness()/2 + .5 + 1.05, -pcX/4 - .5025 - 2.5, 0, "ONLY");
 710
 711 //place chambers into mother volume ALIC
 712   for(int i=1;i<=kNCH;i++){
 713     AliMatrix(idrotm[1000+i],C(i)->ThetaXd(),C(i)->PhiXd(),
 714                              C(i)->ThetaYd(),C(i)->PhiYd(),
 715                              C(i)->ThetaZd(),C(i)->PhiZd());
 716     gMC->Gspos("RICH",i,"ALIC",C(i)->X(),C(i)->Y(),C(i)->Z(),idrotm[1000+i], "ONLY");
 717   }
 718
 719   if(GetDebug())Info("CreateGeometry","Stop.");
 720 }//void AliRICH::CreateGeometry()
 721 //__________________________________________________________________________________________________
 722 void AliRICH::CreateChambers()
 723 {
 724 //create all RICH Chambers on each call. Previous chambers deleted
 725   if(fChambers) delete fChambers;
 726   if(GetDebug())Info("CreateChambers","Creating RICH chambers.");
 727   fChambers=new TObjArray(kNCH);
 728   fChambers->SetOwner();
 729   for(int i=0;i<kNCH;i++)  fChambers->AddAt(new AliRICHChamber(i+1,Param()),i);
 730 }//void AliRICH::CreateChambers()
 731 //__________________________________________________________________________________________________
 732 void AliRICH::GenerateFeedbacks(Int_t iChamber,Float_t eloss)
 733 {
 734 // Generate FeedBack photons
 735 //Determine number of feedback photons
 736   TLorentzVector x4;
 737   gMC->TrackPosition(x4);
 738   Int_t sector;
 739   Int_t iTotQdc=Param()->Loc2TotQdc(C(iChamber)->Glob2Loc(x4),eloss,gMC->TrackPid(),sector);
 740   Int_t iNphotons=gMC->GetRandom()->Poisson(P()->AlphaFeedback(sector)*iTotQdc);
 741   if(GetDebug())Info("GenerateFeedbacks","N photons=%i",iNphotons);
 742   Int_t j;
 743   Float_t cthf, phif, enfp = 0, sthf, e1[3], e2[3], e3[3], vmod, uswop,dir[3], phi,pol[3], mom[4];
 744 //Generate photons
 745   for(Int_t i=0;i<iNphotons;i++){//feddbacks loop
 746     Double_t ranf[2];
 747     gMC->GetRandom()->RndmArray(2,ranf);    //Sample direction
 748     cthf=ranf[0]*2-1.0;
 749     if(cthf<0) continue;
 750     sthf = TMath::Sqrt((1 - cthf) * (1 + cthf));
 751     phif = ranf[1] * 2 * TMath::Pi();
 752
 753     if(Double_t randomNumber=gMC->GetRandom()->Rndm()<=0.57)
 754       enfp = 7.5e-9;
 755     else if(randomNumber<=0.7)
 756       enfp = 6.4e-9;
 757     else
 758       enfp = 7.9e-9;
 759
 760
 761     dir[0] = sthf * TMath::Sin(phif);    dir[1] = cthf;    dir[2] = sthf * TMath::Cos(phif);
 762     gMC->Gdtom(dir, mom, 2);
 763     mom[0]*=enfp;    mom[1]*=enfp;    mom[2]*=enfp;
 764     mom[3] = TMath::Sqrt(mom[0]*mom[0]+mom[1]*mom[1]+mom[2]*mom[2]);
 765
 766     // Polarisation
 767     e1[0]=      0;    e1[1]=-dir[2];    e1[2]= dir[1];
 768     e2[0]=-dir[1];    e2[1]= dir[0];    e2[2]=      0;
 769     e3[0]= dir[1];    e3[1]=      0;    e3[2]=-dir[0];
 770
 771     vmod=0;
 772     for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
 773     if (!vmod) for(j=0;j<3;j++) {
 774       uswop=e1[j];
 775       e1[j]=e3[j];
 776       e3[j]=uswop;
 777     }
 778     vmod=0;
 779     for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
 780     if (!vmod) for(j=0;j<3;j++) {
 781       uswop=e2[j];
 782       e2[j]=e3[j];
 783       e3[j]=uswop;
 784     }
 785
 786     vmod=0;  for(j=0;j<3;j++) vmod+=e1[j]*e1[j];  vmod=TMath::Sqrt(1/vmod);  for(j=0;j<3;j++) e1[j]*=vmod;
 787     vmod=0;  for(j=0;j<3;j++) vmod+=e2[j]*e2[j];  vmod=TMath::Sqrt(1/vmod);  for(j=0;j<3;j++) e2[j]*=vmod;
 788
 789     phi = gMC->GetRandom()->Rndm()* 2 * TMath::Pi();
 790     for(j=0;j<3;j++) pol[j]=e1[j]*TMath::Sin(phi)+e2[j]*TMath::Cos(phi);
 791     gMC->Gdtom(pol, pol, 2);
 792     Int_t outputNtracksStored;
 793     gAlice->GetMCApp()->PushTrack(1,                 //do not transport
 794                      gAlice->GetMCApp()->GetCurrentTrackNumber(),//parent track
 795                      kFeedback,                      //PID
 796                      mom[0],mom[1],mom[2],mom[3],    //track momentum
 797                      x4.X(),x4.Y(),x4.Z(),x4.T(),    //track origin
 798                      pol[0],pol[1],pol[2],           //polarization
 799                      kPFeedBackPhoton,
 800                      outputNtracksStored,
 801                      1.0);
 802   }//feedbacks loop
 803 }//GenerateFeedbacks()
 804 //__________________________________________________________________________________________________