1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
19 ///////////////////////////////////////////////////////////////////////////////
21 // Time Projection Chamber version 2 -- detailed TPC and slow simulation //
25 <img src="picts/AliTPCv2Class.gif">
30 ///////////////////////////////////////////////////////////////////////////////
34 #include <TLorentzVector.h>
37 #include <TVirtualMC.h>
45 #include "AliTPCDigitsArray.h"
46 #include "AliTPCParam.h"
47 #include "AliTPCParamSR.h"
48 #include "AliTPCTrackHitsV2.h"
50 #include "TGeoManager.h"
51 #include "TGeoVolume.h"
56 #include "TGeoCompositeShape.h"
60 //_____________________________________________________________________________
61 AliTPCv2::AliTPCv2(const char *name, const char *title) :
65 // Standard constructor for Time Projection Chamber version 2
69 SetBufferSize(128000);
73 fTPCParam->Write(fTPCParam->GetTitle());
76 //_____________________________________________________________________________
77 void AliTPCv2::CreateGeometry()
80 // Create the geometry of Time Projection Chamber version 2
84 <img src="picts/AliTPC.gif">
89 <img src="picts/AliTPCv2Tree.gif">
93 //----------------------------------------------------------
94 // This geometry is written using TGeo class
95 // Firstly the shapes are defined, and only then the volumes
96 // What is recognized by the MC are volumes
97 //----------------------------------------------------------
99 // tpc - this will be the mother volume
103 // here I define a volume TPC
104 // retrive the medium name with "TPC_" as a leading string
106 TGeoPcon *tpc = new TGeoPcon(0.,360.,18); //18 sections
107 tpc->DefineSection(0,-290.,77.,278.);
108 tpc->DefineSection(1,-259.6,70.,278.);
110 tpc->DefineSection(2,-259.6,68.1,278.);
111 tpc->DefineSection(3,-253.6,68.1,278.);
113 tpc->DefineSection(4,-253.6,68.,278.);
114 tpc->DefineSection(5,-74.0,60.8,278.);
116 tpc->DefineSection(6,-74.0,60.1,278.);
117 tpc->DefineSection(7,-73.3,60.1,278.);
119 tpc->DefineSection(8,-73.3,56.9,278.);
120 tpc->DefineSection(9,73.3,56.9,278.);
122 tpc->DefineSection(10,73.3,60.1,278.);
123 tpc->DefineSection(11,74.0,60.1,278.);
125 tpc->DefineSection(12,74.0,60.8,278.);
126 tpc->DefineSection(13,253.6,65.5,278.);
128 tpc->DefineSection(14,253.6,65.6,278.);
129 tpc->DefineSection(15,259.6,65.6,278.);
131 tpc->DefineSection(16,259.6,70.0,278.);
132 tpc->DefineSection(17,290.,77.,278.);
134 TGeoMedium *m1 = gGeoManager->GetMedium("TPC_Air");
135 TGeoVolume *v1 = new TGeoVolume("TPC_M",tpc,m1);
137 // drift volume - sensitive volume, extended beyond the
138 // endcaps, because of the alignment
140 TGeoPcon *dvol = new TGeoPcon(0.,360.,6);
141 dvol->DefineSection(0,-260.,74.5,264.4);
142 dvol->DefineSection(1,-253.6,74.5,264.4);
144 dvol->DefineSection(2,-253.6,76.6774,258.);
145 dvol->DefineSection(3,253.6,76.6774,258.);
147 dvol->DefineSection(4,253.6,74.5,264.4);
148 dvol->DefineSection(5,260.,74.5,264.4);
150 TGeoMedium *m5 = gGeoManager->GetMedium("TPC_Ne-CO2-N-2");
151 TGeoVolume *v9 = new TGeoVolume("TPC_Drift",dvol,m5);
157 TGeoPcon *tpco = new TGeoPcon(0.,360.,6); //insulator
159 tpco->DefineSection(0,-256.6,264.8,278.);
160 tpco->DefineSection(1,-253.6,264.8,278.);
162 tpco->DefineSection(2,-253.6,258.,278.);
163 tpco->DefineSection(3,250.6,258.,278.);
165 tpco->DefineSection(4,250.6,258.,275.5);
166 tpco->DefineSection(5,253.6,258.,275.5);
168 TGeoMedium *m2 = gGeoManager->GetMedium("TPC_CO2");
169 TGeoVolume *v2 = new TGeoVolume("TPC_OI",tpco,m2);
171 // outer containment vessel
173 TGeoPcon *tocv = new TGeoPcon(0.,360.,6); // containment vessel
175 tocv->DefineSection(0,-256.6,264.8,278.);
176 tocv->DefineSection(1,-253.6,264.8,278.);
178 tocv->DefineSection(2,-253.6,274.8124,278.);
179 tocv->DefineSection(3,247.6,274.8124,278.);
181 tocv->DefineSection(4,247.6,270.4,278.);
182 tocv->DefineSection(5,250.6,270.4,278.);
184 TGeoMedium *m3 = gGeoManager->GetMedium("TPC_Al");
185 TGeoVolume *v3 = new TGeoVolume("TPC_OCV",tocv,m3);
187 TGeoTube *to1 = new TGeoTube(274.8174,277.995,252.1); //epoxy
188 TGeoTube *to2 = new TGeoTube(274.8274,277.985,252.1); //tedlar
189 TGeoTube *to3 = new TGeoTube(274.8312,277.9812,252.1);//prepreg2
190 TGeoTube *to4 = new TGeoTube(274.9062,277.9062,252.1);//nomex
192 TGeoMedium *sm1 = gGeoManager->GetMedium("TPC_Epoxy");
193 TGeoMedium *sm2 = gGeoManager->GetMedium("TPC_Tedlar");
194 TGeoMedium *sm3 = gGeoManager->GetMedium("TPC_Prepreg2");
195 TGeoMedium *sm4 = gGeoManager->GetMedium("TPC_Nomex");
197 TGeoVolume *tov1 = new TGeoVolume("TPC_OCV1",to1,sm1);
198 TGeoVolume *tov2 = new TGeoVolume("TPC_OCV2",to2,sm2);
199 TGeoVolume *tov3 = new TGeoVolume("TPC_OCV3",to3,sm3);
200 TGeoVolume *tov4 = new TGeoVolume("TPC_OCV4",to4,sm4);
201 //-------------------------------------------------------
202 // Tpc Outer Field Cage
203 // daughters - composite (sandwich)
204 //-------------------------------------------------------
206 TGeoPcon *tofc = new TGeoPcon(0.,360.,6);
208 tofc->DefineSection(0,-253.6,258.,269.6);
209 tofc->DefineSection(1,-250.6,258.,269.6);
211 tofc->DefineSection(2,-250.6,258.,260.0676);
212 tofc->DefineSection(3,250.6,258.,260.0676);
214 tofc->DefineSection(4,250.6,258.,275.5);
215 tofc->DefineSection(5,253.6,258.,275.5);
217 TGeoVolume *v4 = new TGeoVolume("TPC_TOFC",tofc,m3);
219 TGeoTube *tf1 = new TGeoTube(258.0,260.0676,252.1); //tedlar
220 TGeoTube *tf2 = new TGeoTube(258.0038,260.0638,252.1); //prepreg3
221 TGeoTube *tf3 = new TGeoTube(258.0338,260.0338,252.1);//nomex
223 TGeoMedium *sm5 = gGeoManager->GetMedium("TPC_Prepreg3");
225 TGeoVolume *tf1v = new TGeoVolume("TPC_OFC1",tf1,sm2);
226 TGeoVolume *tf2v = new TGeoVolume("TPC_OFC2",tf2,sm5);
227 TGeoVolume *tf3v = new TGeoVolume("TPC_OFC3",tf3,sm4);
229 // outer part - positioning
231 tov1->AddNode(tov2,1); tov2->AddNode(tov3,1); tov3->AddNode(tov4,1);
233 tf1v->AddNode(tf2v,1); tf2v->AddNode(tf3v,1);
235 v3->AddNode(tov1,1,new TGeoTranslation(0.,0.,-1.5)); v4->AddNode(tf1v,1);
237 v2->AddNode(v3,1); v2->AddNode(v4,1);
240 //--------------------------------------------------------------------
241 // Tpc Inner INsulator (CO2)
242 // the cones, the central drum and the inner f.c. sandwich with a piece
243 // of the flane will be placed in the TPC
244 //--------------------------------------------------------------------
245 TGeoPcon *tpci = new TGeoPcon(0.,360.,4);
247 tpci->DefineSection(0,-253.6,68.4,76.6774);
248 tpci->DefineSection(1,-74.0,61.2,76.6774);
250 tpci->DefineSection(2,74.0,61.2,76.6774);
252 tpci->DefineSection(3,253.6,65.9,76.6774);
254 TGeoVolume *v5 = new TGeoVolume("TPC_INI",tpci,m2);
256 // now the inner field cage - only part of flanges (2 copies)
258 TGeoTube *tif1 = new TGeoTube(69.9,76.6774,1.5);
259 TGeoVolume *v6 = new TGeoVolume("TPC_IFC1",tif1,m3);
261 //---------------------------------------------------------
262 // Tpc Inner Containment vessel - Muon side
263 //---------------------------------------------------------
264 TGeoPcon *tcms = new TGeoPcon(0.,360.,10);
266 tcms->DefineSection(0,-259.1,68.1,74.2);
267 tcms->DefineSection(1,-253.6,68.1,74.2);
269 tcms->DefineSection(2,-253.6,68.1,68.4);
270 tcms->DefineSection(3,-74.0,60.9,61.2);
272 tcms->DefineSection(4,-74.0,60.1,61.2);
273 tcms->DefineSection(5,-73.3,60.1,61.2);
275 tcms->DefineSection(6,-73.3,56.9,61.2);
276 tcms->DefineSection(7,-73.0,56.9,61.2);
278 tcms->DefineSection(8,-73.0,56.9,58.8);
279 tcms->DefineSection(9,-71.3,56.9,58.8);
281 TGeoVolume *v7 = new TGeoVolume("TPC_ICVM",tcms,m3);
282 //-----------------------------------------------
283 // inner containment vessel - shaft side
284 //-----------------------------------------------
285 TGeoPcon *tcss = new TGeoPcon(0.,360.,10);
287 tcss->DefineSection(0,71.3,56.9,58.8);
288 tcss->DefineSection(1,73.0,56.9,58.8);
290 tcss->DefineSection(2,73.0,56.9,61.2);
291 tcss->DefineSection(3,73.3,56.9,61.2);
293 tcss->DefineSection(4,73.3,60.1,61.2);
294 tcss->DefineSection(5,74.0,60.1,61.2);
296 tcss->DefineSection(6,74.0,60.9,61.2);
297 tcss->DefineSection(7,253.6,65.6,65.9);
299 tcss->DefineSection(8,253.6,65.6,74.2);
300 tcss->DefineSection(9,258.1,65.6,74.2);
302 TGeoVolume *v8 = new TGeoVolume("TPC_ICVS",tcss,m3);
303 //-----------------------------------------------
305 // define 4 parts and make an assembly
306 //-----------------------------------------------
307 // part1 - Al - 2 copies
308 TGeoTube *t1 = new TGeoTube(76.6774,78.845,0.75);
309 TGeoVolume *tv1 = new TGeoVolume("TPC_IFC2",t1,m3);
310 // sandwich - outermost parts - 2 copies
311 TGeoTube *t2 = new TGeoTube(76.6774,78.845,74.175); // tedlar 38 microns
312 TGeoTube *t3 = new TGeoTube(76.6812,78.8412,74.175); // prepreg2 500 microns
313 TGeoTube *t4 = new TGeoTube(76.7312,78.7912,74.175); // prepreg3 300 microns
314 TGeoTube *t5 = new TGeoTube(76.7612,78.7612,74.175); // nomex 2 cm
316 TGeoVolume *tv2 = new TGeoVolume("TPC_IFC3",t2,sm2);
317 TGeoVolume *tv3 = new TGeoVolume("TPC_IFC4",t3,sm3);
318 TGeoVolume *tv4 = new TGeoVolume("TPC_IFC5",t4,sm5);
319 TGeoVolume *tv5 = new TGeoVolume("TPC_IFC6",t5,sm4);
321 // middle parts - 2 copies
322 TGeoTube *t6 = new TGeoTube(76.6774,78.795,5.); // tedlar 38 microns
323 TGeoTube *t7 = new TGeoTube(76.6812,78.7912,5.); // prepreg2 250 microns
324 TGeoTube *t8 = new TGeoTube(76.7062,78.7662,5.); // prepreg3 300 microns
325 TGeoTube *t9 = new TGeoTube(76.7362,78.7362,5.); // nomex 2 cm
327 TGeoVolume *tv6 = new TGeoVolume("TPC_IFC7",t6,sm2);
328 TGeoVolume *tv7 = new TGeoVolume("TPC_IFC8",t7,sm3);
329 TGeoVolume *tv8 = new TGeoVolume("TPC_IFC9",t8,sm5);
330 TGeoVolume *tv9 = new TGeoVolume("TPC_IFC10",t9,sm4);
331 // central part - 1 copy
332 TGeoTube *t10 = new TGeoTube(76.6774,78.745,93.75); // tedlar 38 microns
333 TGeoTube *t11 = new TGeoTube(76.6812,78.7412,93.75); // prepreg3 300 microns
334 TGeoTube *t12 = new TGeoTube(76.7112,78.7112,93.75); // nomex 2 cm
336 TGeoVolume *tv10 = new TGeoVolume("TPC_IFC11",t10,sm2);
337 TGeoVolume *tv11 = new TGeoVolume("TPC_IFC12",t11,sm5);
338 TGeoVolume *tv12 = new TGeoVolume("TPC_IFC13",t12,sm4);
340 // inner part - positioning
342 // creating a sandwich
343 tv2->AddNode(tv3,1); tv3->AddNode(tv4,1); tv4->AddNode(tv5,1);
345 tv6->AddNode(tv7,1); tv7->AddNode(tv8,1); tv8->AddNode(tv9,1);
347 tv10->AddNode(tv11,1); tv11->AddNode(tv12,1);
349 TGeoVolumeAssembly *tv100 = new TGeoVolumeAssembly("TPC_IFC");
351 tv100->AddNode(tv10,1);
352 tv100->AddNode(tv6,1,new TGeoTranslation(0.,0.,-98.75));
353 tv100->AddNode(tv6,2,new TGeoTranslation(0.,0.,98.75));
354 tv100->AddNode(tv2,1,new TGeoTranslation(0.,0.,-177.925));
355 tv100->AddNode(tv2,2,new TGeoTranslation(0.,0.,177.925));
356 tv100->AddNode(tv1,1,new TGeoTranslation(0.,0.,-252.85));
357 tv100->AddNode(tv1,2,new TGeoTranslation(0.,0.,252.85));
359 v5->AddNode(v6,1, new TGeoTranslation(0.,0.,-252.1));
360 v5->AddNode(v6,2, new TGeoTranslation(0.,0.,252.1));
361 v1->AddNode(v5,1); v1->AddNode(v7,1); v1->AddNode(v8,1);
362 v9->AddNode(tv100,1);
368 TGeoPcon *cfl = new TGeoPcon(0.,360.,6);
369 cfl->DefineSection(0,-71.1,59.7,61.2);
370 cfl->DefineSection(1,-68.6,59.7,61.2);
372 cfl->DefineSection(2,-68.6,60.6324,61.2);
373 cfl->DefineSection(3,68.6,60.6324,61.2);
375 cfl->DefineSection(4,68.6,59.7,61.2);
376 cfl->DefineSection(5,71.1,59.7,61.2);
378 TGeoVolume *cflv = new TGeoVolume("TPC_CDR",cfl,m3);
380 TGeoTube *cd1 = new TGeoTube(60.6424,61.19,71.1);
381 TGeoTube *cd2 = new TGeoTube(60.6462,61.1862,71.1);
382 TGeoTube *cd3 = new TGeoTube(60.6662,61.1662,71.1);
384 TGeoMedium *sm6 = gGeoManager->GetMedium("TPC_Prepreg1");
385 TGeoVolume *cd1v = new TGeoVolume("TPC_CDR1",cd1,sm2); //tedlar
386 TGeoVolume *cd2v = new TGeoVolume("TPC_CDR2",cd2,sm6);// prepreg1
387 TGeoVolume *cd3v = new TGeoVolume("TPC_CDR3",cd3,sm4); //nomex
389 // seals for central drum 2 copies
391 TGeoTube *cs = new TGeoTube(56.9,61.2,0.1);
392 TGeoMedium *sm7 = gGeoManager->GetMedium("TPC_Mylar");
393 TGeoVolume *csv = new TGeoVolume("TPC_CDRS",cs,sm7);
394 v1->AddNode(csv,1,new TGeoTranslation(0.,0.,-71.));
395 v1->AddNode(csv,2,new TGeoTranslation(0.,0.,71.));
398 TGeoPcon *se = new TGeoPcon(0.,360.,6);
399 se->DefineSection(0,-72.8,59.7,61.2);
400 se->DefineSection(1,-72.3,59.7,61.2);
402 se->DefineSection(2,-72.3,58.85,61.2);
403 se->DefineSection(3,-71.6,58.85,61.2);
405 se->DefineSection(4,-71.6,59.7,61.2);
406 se->DefineSection(5,-71.3,59.7,61.2);
408 TGeoVolume *sev = new TGeoVolume("TPC_CDCE",se,m3);
410 TGeoTube *si = new TGeoTube(56.9,58.8,1.);
411 TGeoVolume *siv = new TGeoVolume("TPC_CDCI",si,m3);
413 // define reflection matrix
415 TGeoRotation *ref = new TGeoRotation("ref",90.,0.,90.,90.,180.,0.);
417 cd1v->AddNode(cd2v,1); cd2v->AddNode(cd3v,1); cflv->AddNode(cd1v,1);
419 v1->AddNode(siv,1,new TGeoTranslation(0.,0.,-70.1));
420 v1->AddNode(siv,2,new TGeoTranslation(0.,0.,70.1));
421 v1->AddNode(sev,1); v1->AddNode(sev,2,ref); v1->AddNode(cflv,1);
423 // central membrane - 2 rings and a mylar membrane - assembly
425 TGeoTube *ih = new TGeoTube(81.05,84.05,0.3);
426 TGeoTube *oh = new TGeoTube(250.,256.,.5);
427 TGeoTube *mem = new TGeoTube(84.05,250,0.01);
428 TGeoVolume *ihv = new TGeoVolume("TPC_IHVH",ih,m3);
429 TGeoVolume *ohv = new TGeoVolume("TPC_OHVH",oh,m3);
430 TGeoVolume *memv = new TGeoVolume("TPC_HV",mem,sm7);
432 TGeoVolumeAssembly *cm = new TGeoVolumeAssembly("TPC_HVMEM");
438 // end caps - they are make as an assembly of single segments
439 // containing both readout chambers
441 Double_t OpeningAngle = 10.*TMath::DegToRad();
442 Double_t thick=1.5; // rib
443 Double_t shift = thick/TMath::Sin(OpeningAngle);
445 Double_t LowEdge = 86.3; // hole in the wheel
446 Double_t UpEdge = 240.4; // hole in the wheel
448 new TGeoTubeSeg("sec",74.5,264.4,3.,0.,20.);
450 TGeoPgon *hole = new TGeoPgon("hole",0.,20.,1,4);
452 hole->DefineSection(0,-3.5,LowEdge-shift,UpEdge-shift);
453 hole->DefineSection(1,-1.5,LowEdge-shift,UpEdge-shift);
455 hole->DefineSection(2,-1.5,LowEdge-shift,UpEdge+3.-shift);
456 hole->DefineSection(3,3.5,LowEdge-shift,UpEdge+3.-shift);
458 Double_t ys = shift*TMath::Sin(OpeningAngle);
459 Double_t xs = shift*TMath::Cos(OpeningAngle);
460 TGeoTranslation *tr = new TGeoTranslation("tr",xs,ys,0.);
461 tr->RegisterYourself();
462 TGeoCompositeShape *chamber = new TGeoCompositeShape("sec-hole:tr");
463 TGeoVolume *sv = new TGeoVolume("TPC_WSEG",chamber,m3);
464 TGeoPgon *bar = new TGeoPgon("bar",0.,20.,1,2);
465 bar->DefineSection(0,-3.,131.5-shift,136.5-shift);
466 bar->DefineSection(1,1.5,131.5-shift,136.5-shift);
467 TGeoVolume *barv = new TGeoVolume("TPC_WBAR",bar,m3);
468 TGeoVolumeAssembly *ch = new TGeoVolumeAssembly("TPC_WCH");//empty segment
470 ch->AddNode(sv,1); ch->AddNode(barv,1,tr);
476 TGeoTrd1 *ibody = new TGeoTrd1(13.8742,21.3328,4.29,21.15);
477 TGeoVolume *ibdv = new TGeoVolume("TPC_IROCB",ibody,m3);
479 TGeoTrd1 *emp = new TGeoTrd1(12.3742,19.8328,3.99,19.65);
480 TGeoVolume *empv = new TGeoVolume("TPC_IROCE",emp,m1);
481 ibdv->AddNode(empv,1,new TGeoTranslation(0.,-0.3,0.));
483 Double_t tga = (19.8328-12.3742)/39.3;
485 xmin = 9.55*tga+12.3742;
486 xmax = 9.95*tga+12.3742;
487 TGeoTrd1 *ib1 = new TGeoTrd1(xmin,xmax,3.29,0.2);
488 TGeoVolume *ib1v = new TGeoVolume("TPC_IRB1",ib1,m3);
489 empv->AddNode(ib1v,1,new TGeoTranslation("tt1",0.,0.7,-9.9));
490 xmin=19.4*tga+12.3742;
491 xmax=19.9*tga+12.3742;
492 TGeoTrd1 *ib2 = new TGeoTrd1(xmin,xmax,3.29,0.25);
493 TGeoVolume *ib2v = new TGeoVolume("TPC_TRB2",ib2,m3);
494 empv->AddNode(ib2v,1,new TGeoTranslation(0.,0.7,0.));
495 xmin=29.35*tga+12.3742;
496 xmax=29.75*tga+12.3742;
497 TGeoTrd1 *ib3 = new TGeoTrd1(xmin,xmax,3.29,0.2);
498 TGeoVolume *ib3v = new TGeoVolume("TPC_IRB3",ib3,m3);
499 empv->AddNode(ib3v,1,new TGeoTranslation(0.,0.7,9.9));
501 // holes for connectors
503 TGeoBBox *conn = new TGeoBBox(0.4,0.3,4.675); // identical for iroc and oroc
504 TGeoVolume *connv = new TGeoVolume("TPC_RCCON",conn,m1);
505 TString fileName(gSystem->Getenv("ALICE_ROOT"));
506 fileName += "/TPC/conn_iroc.dat";
508 in.open(fileName.Data(), ios_base::in); // asci file
509 for(Int_t i =0;i<86;i++){
514 TGeoRotation *rrr = new TGeoRotation();
516 TGeoCombiTrans *trans = new TGeoCombiTrans("trans",x,y,z,rrr);
517 ibdv->AddNode(connv,i+1,trans);
521 new TGeoTrd1("icap",14.5974,23.3521,1.19,24.825);
523 new TGeoTrd1("ihole",13.8742,21.3328,1.2,21.15);
524 TGeoTranslation *tr1 = new TGeoTranslation("tr1",0.,0.,1.725);
525 tr1->RegisterYourself();
526 TGeoCompositeShape *ic = new TGeoCompositeShape("icap-ihole:tr1");
527 TGeoVolume *icv = new TGeoVolume("TPC_IRCAP",ic,m3);
529 // pad plane and wire fixations
531 TGeoTrd1 *pp = new TGeoTrd1(14.5974,23.3521,0.3,24.825); //pad+iso
532 TGeoMedium *m4 = gGeoManager->GetMedium("TPC_G10");
533 TGeoVolume *ppv = new TGeoVolume("TPC_IRPP",pp,m4);
534 TGeoPara *f1 = new TGeoPara(.6,.5,24.825,0.,-10.,0.);
535 TGeoVolume *f1v = new TGeoVolume("TPC_IRF1",f1,m4);
536 TGeoPara *f2 = new TGeoPara(.6,.5,24.825,0.,10.,0.);
537 TGeoVolume *f2v = new TGeoVolume("TPC_IRF2",f2,m4);
539 TGeoVolumeAssembly *iroc = new TGeoVolumeAssembly("TPC_IROC");
541 iroc->AddNode(ibdv,1);
542 iroc->AddNode(icv,1,new TGeoTranslation(0.,3.1,-1.725));
543 iroc->AddNode(ppv,1,new TGeoTranslation(0.,4.59,-1.725));
544 tga =(23.3521-14.5974)/49.65;
545 Double_t xx = 24.825*tga+14.5974-0.6;
546 iroc->AddNode(f1v,1,new TGeoTranslation(-xx,5.39,-1.725));
547 iroc->AddNode(f2v,1,new TGeoTranslation(xx,5.39,-1.725));
551 TGeoTrd1 *obody = new TGeoTrd1(22.2938,40.5084,4.19,51.65);
552 TGeoVolume *obdv = new TGeoVolume("TPC_OROCB",obody,m3);
553 TGeoTrd1 *oemp = new TGeoTrd1(20.2938,38.5084,3.89,49.65);
554 TGeoVolume *oempv = new TGeoVolume("TPC_OROCE",oemp,m1);
555 obdv->AddNode(oempv,1,new TGeoTranslation(0.,-0.3,0.));
557 tga=(38.5084-20.2938)/99.3;
558 xmin=tga*10.2+20.2938;
559 xmax=tga*10.6+20.2938;
560 TGeoTrd1 *ob1 = new TGeoTrd1(xmin,xmax,2.915,0.2);
561 TGeoVolume *ob1v = new TGeoVolume("TPC_ORB1",ob1,m3);
563 xmin=22.55*tga+20.2938;
564 xmax=24.15*tga+20.2938;
565 TGeoTrd1 *ob2 = new TGeoTrd1(xmin,xmax,2.915,0.8);
566 TGeoVolume *ob2v = new TGeoVolume("TPC_ORB2",ob2,m3);
568 xmin=36.1*tga+20.2938;
569 xmax=36.5*tga+20.2938;
570 TGeoTrd1 *ob3 = new TGeoTrd1(xmin,xmax,2.915,0.2);
571 TGeoVolume *ob3v = new TGeoVolume("TPC_ORB3",ob3,m3);
573 xmin=49.0*tga+20.2938;
574 xmax=50.6*tga+20.2938;
575 TGeoTrd1 *ob4 = new TGeoTrd1(xmin,xmax,2.915,0.8);
576 TGeoVolume *ob4v = new TGeoVolume("TPC_ORB4",ob4,m3);
578 xmin=63.6*tga+20.2938;
579 xmax=64.0*tga+20.2938;
580 TGeoTrd1 *ob5 = new TGeoTrd1(xmin,xmax,2.915,0.2);
581 TGeoVolume *ob5v = new TGeoVolume("TPC_ORB5",ob5,m3);
583 xmin=75.5*tga+20.2938;
584 xmax=77.15*tga+20.2938;
585 TGeoTrd1 *ob6 = new TGeoTrd1(xmin,xmax,2.915,0.8);
586 TGeoVolume *ob6v = new TGeoVolume("TPC_ORB6",ob6,m3);
588 xmin=88.7*tga+20.2938;
589 xmax=89.1*tga+20.2938;
590 TGeoTrd1 *ob7 = new TGeoTrd1(xmin,xmax,2.915,0.2);
591 TGeoVolume *ob7v = new TGeoVolume("TPC_ORB7",ob7,m3);
593 oempv->AddNode(ob1v,1,new TGeoTranslation(0.,0.975,-39.25));
594 oempv->AddNode(ob2v,1,new TGeoTranslation(0.,0.975,-26.3));
595 oempv->AddNode(ob3v,1,new TGeoTranslation(0.,0.975,-13.35));
596 oempv->AddNode(ob4v,1,new TGeoTranslation(0.,0.975,0.15));
597 oempv->AddNode(ob5v,1,new TGeoTranslation(0.,0.975,14.15));
598 oempv->AddNode(ob6v,1,new TGeoTranslation(0.,0.975,26.7));
599 oempv->AddNode(ob7v,1,new TGeoTranslation(0.,0.975,39.25));
601 TGeoBBox *ob8 = new TGeoBBox(0.8,2.915,5.1);
602 TGeoBBox *ob9 = new TGeoBBox(0.8,2.915,5.975);
603 TGeoBBox *ob10 = new TGeoBBox(0.8,2.915,5.775);
604 TGeoBBox *ob11 = new TGeoBBox(0.8,2.915,6.25);
605 TGeoBBox *ob12 = new TGeoBBox(0.8,2.915,6.5);
607 TGeoVolume *ob8v = new TGeoVolume("TPC_ORB8",ob8,m3);
608 TGeoVolume *ob9v = new TGeoVolume("TPC_ORB9",ob9,m3);
609 TGeoVolume *ob10v = new TGeoVolume("TPC_ORB10",ob10,m3);
610 TGeoVolume *ob11v = new TGeoVolume("TPC_ORB11",ob11,m3);
611 TGeoVolume *ob12v = new TGeoVolume("TPC_ORB12",ob12,m3);
613 oempv->AddNode(ob8v,1,new TGeoTranslation(0.,0.975,-44.55));
614 oempv->AddNode(ob8v,2,new TGeoTranslation(0.,0.975,44.55));
615 oempv->AddNode(ob9v,1,new TGeoTranslation(0.,0.975,-33.075));
616 oempv->AddNode(ob9v,2,new TGeoTranslation(0.,0.975,-19.525));
617 oempv->AddNode(ob10v,1,new TGeoTranslation(0.,0.975,20.125));
618 oempv->AddNode(ob10v,2,new TGeoTranslation(0.,0.975,33.275));
619 oempv->AddNode(ob11v,1,new TGeoTranslation(0.,0.975,-6.9));
620 oempv->AddNode(ob12v,1,new TGeoTranslation(0.,0.975,7.45));
622 // holes for connectors
624 fileName = gSystem->Getenv("ALICE_ROOT");
625 fileName += "/TPC/conn_oroc.dat";
626 in.open(fileName.Data(), ios_base::in); // asci file
627 for(Int_t i =0;i<78;i++){
630 Double_t x1,z1,x2,z2;
632 Double_t xr = 4.7*TMath::Sin(ang*TMath::DegToRad());
633 Double_t zr = 4.7*TMath::Cos(ang*TMath::DegToRad());
635 x1=xr+x; x2=-xr+x; z1=zr+z; z2 = -zr+z;
637 TGeoRotation *rr = new TGeoRotation();
641 TGeoCombiTrans *trans1 = new TGeoCombiTrans("trans1",x1,y,z1,rr);
642 TGeoCombiTrans *trans2 = new TGeoCombiTrans("trans2",x2,y,z2,rr);
643 obdv->AddNode(connv,i+1,trans1);
644 obdv->AddNode(connv,i+79,trans2);
648 new TGeoTrd1("ocap",23.3874,43.5239,1.09,57.1);
649 new TGeoTrd1("ohole",22.2938,40.5084,1.09,51.65);
650 TGeoTranslation *tr5 = new TGeoTranslation("tr5",0.,0.,-2.15);
651 tr5->RegisterYourself();
652 TGeoCompositeShape *oc = new TGeoCompositeShape("ocap-ohole:tr5");
653 TGeoVolume *ocv = new TGeoVolume("TPC_ORCAP",oc,m3);
655 // pad plane and wire fixations
657 TGeoTrd1 *opp = new TGeoTrd1(23.3874,43.5239,0.3,57.1);
658 TGeoVolume *oppv = new TGeoVolume("TPC_ORPP",opp,m4);
660 tga=(43.5239-23.3874)/114.2;
661 TGeoPara *f3 = new TGeoPara(.7,.6,57.1,0.,-10.,0.);
662 TGeoPara *f4 = new TGeoPara(.7,.6,57.1,0.,10.,0.);
663 xx = 57.1*tga+23.3874-0.7;
664 TGeoVolume *f3v = new TGeoVolume("TPC_ORF1",f3,m4);
665 TGeoVolume *f4v = new TGeoVolume("TPC_ORF2",f4,m4);
667 TGeoVolumeAssembly *oroc = new TGeoVolumeAssembly("TPC_OROC");
669 oroc->AddNode(obdv,1);
670 oroc->AddNode(ocv,1,new TGeoTranslation(0.,3.1,2.15));
671 oroc->AddNode(oppv,1,new TGeoTranslation(0.,4.49,2.15));
672 oroc->AddNode(f3v,1,new TGeoTranslation(-xx,5.39,2.15));
673 oroc->AddNode(f4v,1,new TGeoTranslation(xx,5.39,2.15));
675 // now iroc and oroc are placed into a sector...
677 TGeoVolumeAssembly *sect = new TGeoVolumeAssembly("TPC_SECT");
678 TGeoRotation rot1("rot1",90.,90.,0.);
679 TGeoRotation rot2("rot2");
681 TGeoRotation *rot = new TGeoRotation("rot");
685 x0=110.2*TMath::Cos(OpeningAngle);
686 y0=110.2*TMath::Sin(OpeningAngle);
687 TGeoCombiTrans *combi1 = new TGeoCombiTrans("combi1",x0,y0,1.09,rot);
688 x0=188.45*TMath::Cos(OpeningAngle);
689 y0=188.45*TMath::Sin(OpeningAngle);
690 TGeoCombiTrans *combi2 = new TGeoCombiTrans("combi2",x0,y0,0.99,rot);
693 sect->AddNode(iroc,1,combi1);
694 sect->AddNode(oroc,1,combi2);
696 // segment is ready...
697 // now I try to make a wheel...
699 TGeoVolumeAssembly *wheel = new TGeoVolumeAssembly("TPC_ENDCAP");
701 for(Int_t i =0;i<18;i++){
702 Double_t phi = (20.*i);
703 TGeoRotation *r = new TGeoRotation();
705 wheel->AddNode(sect,i+1,r);
708 // wheels in the drift volume!
709 TGeoCombiTrans *combi3 = new TGeoCombiTrans("combi3",0.,0.,256.6,ref);
710 v9->AddNode(wheel,1,combi3);
711 v9->AddNode(wheel,2,new TGeoTranslation(0.,0.,-256.6));
712 //_____________________________________________________________
713 // service support wheel
714 //_____________________________________________________________
715 TGeoPgon *sw = new TGeoPgon(0.,20.,1,2);
716 sw->DefineSection(0,-4.,80.5,251.75);
717 sw->DefineSection(1,4.,80.5,251.75);
718 TGeoVolume *swv = new TGeoVolume("TPC_SWSEG",sw,m3); //Al
721 shift = thick/TMath::Sin(OpeningAngle);
722 TGeoPgon *sh = new TGeoPgon(0.,20.,1,2);
723 sh->DefineSection(0,-4.,81.5-shift,250.75-shift);
724 sh->DefineSection(1,4.,81.5-shift,250.75-shift);
725 TGeoVolume *shv = new TGeoVolume("TPC_SWS1",sh,m1); //Air
727 TGeoMedium *m9 = gGeoManager->GetMedium("TPC_Si");
728 TGeoPgon *el = new TGeoPgon(0.,20.,1,2);
729 el->DefineSection(0,-1.872,81.5-shift,250.75-shift);
730 el->DefineSection(1,1.872,81.5-shift,250.75-shift);
731 TGeoVolume *elv = new TGeoVolume("TPC_ELEC",el,m9); //Si
736 ys = shift*TMath::Sin(OpeningAngle);
737 xs = shift*TMath::Cos(OpeningAngle);
738 swv->AddNode(shv,1,new TGeoTranslation(xs,ys,0.));
740 TGeoPgon *co = new TGeoPgon(0.,20.,1,2);
741 co->DefineSection(0,-0.5,77.,255.25);
742 co->DefineSection(1,0.5,77.,255.25);
743 TGeoVolume *cov = new TGeoVolume("TPC_SWC1",co,m3);//Al
745 TGeoPgon *coh = new TGeoPgon(0.,20.,1,2);
746 shift=4./TMath::Sin(OpeningAngle);
747 coh->DefineSection(0,-0.5,85.-shift,247.25-shift);
748 coh->DefineSection(1,0.5,85.-shift,247.25-shift);
750 TGeoVolume *cohv = new TGeoVolume("TPC_SWC2",coh,m1);
752 ys = shift*TMath::Sin(OpeningAngle);
753 xs = shift*TMath::Cos(OpeningAngle);
754 cov->AddNode(cohv,1,new TGeoTranslation(xs,ys,0.));
756 // Sector as an Assembly
758 TGeoVolumeAssembly *swhs = new TGeoVolumeAssembly("TPC_SSWSEC");
759 swhs->AddNode(swv,1);
760 swhs->AddNode(cov,1,new TGeoTranslation(0.,0.,-4.5));
761 swhs->AddNode(cov,2,new TGeoTranslation(0.,0.,4.5));
763 // SSW as an Assembly of sectors
765 TGeoVolumeAssembly *swheel = new TGeoVolumeAssembly("TPC_SSWHEEL");
766 for(Int_t i =0;i<18;i++){
767 Double_t phi = (20.*i);
768 TGeoRotation *r = new TGeoRotation();
770 swheel->AddNode(swhs,i+1,r);
772 v1->AddNode(swheel,1,new TGeoTranslation(0.,0.,-284.6));
773 v1->AddNode(swheel,2,new TGeoTranslation(0.,0.,284.6));
775 // sensitive strips - strip "0" is always set
778 totrows = fTPCParam->GetNRowLow() + fTPCParam->GetNRowUp();
781 gGeoManager->Volume("TPC_Strip","PGON",m5->GetId(),upar);
782 upar=new Double_t [10];
791 Double_t rlow=fTPCParam->GetPadRowRadiiLow(0);
798 gGeoManager->Node("TPC_Strip",1,"TPC_Drift",0.,0.,124.82,0,kTRUE,upar,10);
799 gGeoManager->Node("TPC_Strip",totrows+1,
800 "TPC_Drift",0.,0.,-124.82,0,kTRUE,upar,10);
802 // now, strips optionally
806 for(Int_t i=2;i<fTPCParam->GetNRowLow()+1;i++){
807 rlow=fTPCParam->GetPadRowRadiiLow(i-1);
812 gGeoManager->Node("TPC_Strip",i,
813 "TPC_Drift",0.,0.,124.82,0,kTRUE,upar,10);
814 gGeoManager->Node("TPC_Strip",totrows+i,
815 "TPC_Drift",0.,0.,-124.82,0,kTRUE,upar,10);
818 for(Int_t i=1;i<fTPCParam->GetNRowUp()+1;i++){
819 rlow=fTPCParam->GetPadRowRadiiUp(i-1);
824 gGeoManager->Node("TPC_Strip",i+fTPCParam->GetNRowLow(),
825 "TPC_Drift",0.,0.,124.82,0,kTRUE,upar,10);
826 gGeoManager->Node("TPC_Strip",totrows+i+fTPCParam->GetNRowLow(),
827 "TPC_Drift",0.,0.,-124.82,0,kTRUE,upar,10);
830 //----------------------------------------------------------
831 // TPc Support Rods - MAKROLON
832 //----------------------------------------------------------
833 TGeoMedium *m6=gGeoManager->GetMedium("TPC_Makrolon");
834 TGeoMedium *m7=gGeoManager->GetMedium("TPC_Cu");
835 // upper and lower rods differ in length!
838 gGeoManager->Volume("TPC_Rod","TUBE",m6->GetId(),upar);
839 upar=new Double_t [3];
844 //HV rods - makrolon + 0.58cm (diameter) Cu
845 TGeoTube *hvr = new TGeoTube(0.,2.2,126.64);
846 TGeoTube *hvc = new TGeoTube(0.,0.29,126.64);
848 TGeoVolume *hvrv = new TGeoVolume("TPC_HV_Rod",hvr,m6);
849 TGeoVolume *hvcv = new TGeoVolume("TPC_HV_Cable",hvc,m7);
850 hvrv->AddNode(hvcv,1);
852 for(Int_t i=0;i<18;i++){
855 angle=TMath::DegToRad()*20.*(Double_t)i;
857 x=r * TMath::Cos(angle);
858 y=r * TMath::Sin(angle);
859 upar[2]=126.64; //lower
862 v9->AddNode(hvrv,1,new TGeoTranslation(x,y,z));
863 v9->AddNode(hvrv,2,new TGeoTranslation(x,y,-z));
866 gGeoManager->Node("TPC_Rod",i+1,"TPC_Drift",x,y,z,0,kTRUE,upar,3);//shaft
867 gGeoManager->Node("TPC_Rod",i+18,"TPC_Drift",x,y,-z,0,kTRUE,upar,3);//muon
870 x=r * TMath::Cos(angle);
871 y=r * TMath::Sin(angle);
872 upar[2]=126.54; //upper
874 gGeoManager->Node("TPC_Rod",i+36,"TPC_Drift",x,y,z,0,kTRUE,upar,3);
875 gGeoManager->Node("TPC_Rod",i+54,"TPC_Drift",x,y,-z,0,kTRUE,upar,3);
878 TGeoVolume *alice = gGeoManager->GetVolume("ALIC");
879 alice->AddNode(v1,1);
884 //_____________________________________________________________________________
885 void AliTPCv2::DrawDetector()
888 // Draw a shaded view of the Time Projection Chamber version 1
891 // Set everything unseen
892 gMC->Gsatt("*", "seen", -1);
894 // Set ALIC mother transparent
895 gMC->Gsatt("ALIC","SEEN",0);
897 // Set the volumes visible
900 gMC->Gsatt("TPC ","SEEN",0);
901 gMC->Gsatt("TOIN","SEEN",1);
902 gMC->Gsatt("TOIN","COLO",7);
903 gMC->Gsatt("TOCV","SEEN",1);
904 gMC->Gsatt("TOCV","COLO",4);
905 gMC->Gsatt("TSA1","SEEN",0);
906 gMC->Gsatt("TSA2","SEEN",0);
907 gMC->Gsatt("TSA3","SEEN",0);
908 gMC->Gsatt("TSA4","SEEN",0);
909 gMC->Gsatt("TSA5","SEEN",0);
910 gMC->Gsatt("TOFC","SEEN",1);
911 gMC->Gsatt("TOFC","COLO",4);
912 gMC->Gsatt("TSA6","SEEN",0);
913 gMC->Gsatt("TSA7","SEEN",0);
914 gMC->Gsatt("TSA8","SEEN",0);
915 gMC->Gsatt("TIIN","SEEN",1);
916 gMC->Gsatt("TIIN","COLO",7);
917 gMC->Gsatt("TII1","SEEN",0);
918 gMC->Gsatt("TIFC","SEEN",1);
919 gMC->Gsatt("TIFC","COLO",4);
920 gMC->Gsatt("TSA9","SEEN",0);
921 gMC->Gsatt("TS10","SEEN",0);
922 gMC->Gsatt("TS11","SEEN",0);
923 gMC->Gsatt("TS12","SEEN",0);
924 gMC->Gsatt("TS13","SEEN",0);
925 gMC->Gsatt("TS14","SEEN",0);
926 gMC->Gsatt("TICC","SEEN",0);
927 gMC->Gsatt("TICM","SEEN",0);
928 gMC->Gsatt("TS15","SEEN",0);
929 gMC->Gsatt("TS16","SEEN",0);
930 gMC->Gsatt("TS17","SEEN",0);
931 gMC->Gsatt("TS18","SEEN",0);
932 gMC->Gsatt("TS19","SEEN",0);
933 gMC->Gsatt("TPJ1","SEEN",0);
934 gMC->Gsatt("TPJ2","SEEN",0);
935 gMC->Gsatt("TICS","SEEN",0);
936 gMC->Gsatt("TDGN","SEEN",0);
937 gMC->Gsatt("TIRC","SEEN",0);
938 gMC->Gsatt("TIC1","SEEN",1);
939 gMC->Gsatt("TIPP","SEEN",0);
940 gMC->Gsatt("TIC3","SEEN",0);
941 gMC->Gsatt("TRCE","SEEN",0);
942 gMC->Gsatt("TPSC","SEEN",0);
943 gMC->Gsatt("TPCC","SEEN",0);
944 gMC->Gsatt("TORC","SEEN",0);
945 gMC->Gsatt("TOPP","SEEN",0);
946 gMC->Gsatt("TOC3","SEEN",0);
947 gMC->Gsatt("TOC1","SEEN",1);
948 gMC->Gsatt("TSSW","SEEN",1);
949 gMC->Gsatt("TSWC","SEEN",1);
950 gMC->Gsatt("TSSW","COLO",3);
951 gMC->Gsatt("TSWC","COLO",3);
952 gMC->Gsatt("TSCE","COLO",6);
953 gMC->Gsatt("TSCE","SEEN",1);
954 gMC->Gsatt("TWES","SEEN",0);
955 gMC->Gsatt("TSWB","SEEN",0);
956 gMC->Gsatt("TPEL","SEEN",0);
957 gMC->Gsatt("TPMW","SEEN",1);
958 gMC->Gsatt("TESR","SEEN",1);
959 gMC->Gsatt("TPMW","COLO",12);
960 gMC->Gsatt("TIC1","COLO",5);
961 gMC->Gsatt("TOC1","COLO",5);
962 gMC->Gsatt("TESB","SEEN",0);
963 gMC->Gsatt("THVM","SEEN",1);
964 gMC->Gsatt("THVM","COLO",11);
965 gMC->Gsatt("THVH","SEEN",0);
966 gMC->Gsatt("TPSR","SEEN",0);
967 gMC->Gsatt("THVL","SEEN",0);
968 gMC->Gsatt("THVC","SEEN",0);
969 gMC->Gsatt("THVE","SEEN",0);
970 gMC->Gsatt("THVR","SEEN",0);
971 gMC->Gsatt("TPSS","SEEN",0);
972 gMC->Gsatt("TPUS","SEEN",0);
973 gMC->Gsatt("TPLS","SEEN",0);
976 gMC->Gdopt("hide", "on");
977 gMC->Gdopt("shad", "on");
978 gMC->Gsatt("*", "fill", 7);
979 gMC->SetClipBox(".");
980 gMC->SetClipBox("TPMW",-300,300,-300,300,254.,270.);
981 gMC->SetClipBox("TESR",-300,300,-300,300,254.,270.);
982 gMC->SetClipBox("TSSW",-300,300,-300,300,283.,284.);
983 gMC->SetClipBox("TSWC",-300,300,-300,300,283.,284.);
984 gMC->SetClipBox("*", 0, 300, -300, 300, -290, 290);
986 gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025);
987 gMC->Gdhead(1111, "Time Projection Chamber");
988 gMC->Gdman(18, 4, "MAN");
989 gMC->Gdopt("hide","off");
992 //_____________________________________________________________________________
993 void AliTPCv2::CreateMaterials()
996 // Define materials for version 2 of the Time Projection Chamber
999 AliTPC::CreateMaterials();
1002 //_____________________________________________________________________________
1003 void AliTPCv2::Init()
1006 // Initialises version 2 of the TPC after that it has been built
1009 Int_t *idtmed = fIdtmed->GetArray();
1014 fIdSens=gMC->VolId("TPC_Strip"); // one strip is always selected...
1016 fIDrift=gMC->VolId("TPC_Drift");
1017 fSecOld=-100; // fake number
1019 gMC->SetMaxNStep(30000); // max. number of steps increased
1021 gMC->Gstpar(idtmed[2],"LOSS",5); // specific energy loss
1023 AliInfo("*** TPC version 2 initialized ***");
1024 AliInfo(Form("Maximum number of steps = %d",gMC->GetMaxNStep()));
1030 //_____________________________________________________________________________
1031 void AliTPCv2::StepManager()
1034 // Called for every step in the Time Projection Chamber
1038 // parameters used for the energy loss calculations
1040 const Float_t kprim = 14.35; // number of primary collisions per 1 cm
1041 const Float_t kpoti = 20.77e-9; // first ionization potential for Ne/CO2
1042 const Float_t kwIon = 35.97e-9; // energy for the ion-electron pair creation
1045 const Float_t kbig = 1.e10;
1052 vol[1]=0; // preset row number to 0
1054 gMC->SetMaxStep(kbig);
1056 if(!gMC->IsTrackAlive()) return; // particle has disappeared
1058 Float_t charge = gMC->TrackCharge();
1060 if(TMath::Abs(charge)<=0.) return; // take only charged particles
1062 // check the sensitive volume
1064 id = gMC->CurrentVolID(copy); // vol ID and copy number (starts from 1!)
1065 if(id != fIDrift && id != fIdSens) return; // not in the sensitive folume
1067 gMC->TrackPosition(p);
1068 Double_t r = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
1072 Double_t angle = TMath::ACos(p[0]/r);
1073 angle = (p[1]<0.) ? TMath::TwoPi()-angle : angle;
1075 // angular segment, it is not a real sector number...
1077 Int_t sector=TMath::Nint((angle-fTPCParam->GetInnerAngleShift())/
1078 fTPCParam->GetInnerAngle());
1079 // rotate to segment "0"
1081 fTPCParam->AdjustCosSin(sector,cos,sin);
1082 Float_t x1=p[0]*cos + p[1]*sin;
1083 // check if within sector's limits
1084 if(x1>=fTPCParam->GetInnerRadiusLow()&&x1<=fTPCParam->GetInnerRadiusUp()
1085 ||x1>=fTPCParam->GetOuterRadiusLow()&&x1<=fTPCParam->GetOuterRadiusUp()){
1086 // calculate real sector number...
1087 if (x1>fTPCParam->GetOuterRadiusLow()){
1088 sector = TMath::Nint((angle-fTPCParam->GetOuterAngleShift())/
1089 fTPCParam->GetOuterAngle())+fTPCParam->GetNInnerSector();
1090 if (p[2]<0) sector+=(fTPCParam->GetNOuterSector()>>1);
1093 if (p[2]<0) sector+=(fTPCParam->GetNInnerSector()>>1);
1095 // here I have a sector number
1099 // check if change of sector
1100 if(sector != fSecOld){
1102 // add track reference
1103 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
1105 // track is in the sensitive strip
1107 // track is entering the strip
1108 if (gMC->IsTrackEntering()){
1109 Int_t totrows = fTPCParam->GetNRowLow()+fTPCParam->GetNRowUp();
1110 vol[1] = (copy<=totrows) ? copy-1 : copy-1-totrows;
1111 // row numbers are autonomous for lower and upper sectors
1112 if(vol[0] > fTPCParam->GetNInnerSector()) {
1113 vol[1] -= fTPCParam->GetNRowLow();
1116 if(vol[0]<fTPCParam->GetNInnerSector()&&vol[1] == 0){
1118 // lower sector, row 0, because Jouri wants to have this
1120 gMC->TrackMomentum(p);
1124 hits[3]=0.; // this hit has no energy loss
1125 // Get also the track time for pileup simulation
1126 hits[4]=gMC->TrackTime();
1128 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(), vol,hits);
1132 gMC->TrackPosition(p);
1136 hits[3]=0.; // this hit has no energy loss
1137 // Get also the track time for pileup simulation
1138 hits[4]=gMC->TrackTime();
1140 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(), vol,hits);
1145 //-----------------------------------------------------------------
1146 // charged particle is in the sensitive drift volume
1147 //-----------------------------------------------------------------
1148 if(gMC->TrackStep() > 0) {
1150 Int_t nel = (Int_t)(((gMC->Edep())-kpoti)/kwIon) + 1;
1151 nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV
1153 gMC->TrackPosition(p);
1157 hits[3]=(Float_t)nel;
1162 gMC->TrackMomentum(p);
1163 Float_t momentum = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
1164 Float_t precision = (momentum>0.1) ? 0.002 :0.01;
1165 fTrackHits->SetHitPrecision(precision);
1168 // Get also the track time for pileup simulation
1169 hits[4]=gMC->TrackTime();
1171 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(), vol,hits);
1174 } //within sector's limits
1175 // Stemax calculation for the next step
1179 gMC->TrackMomentum(mom);
1180 Float_t ptot=mom.Rho();
1181 Float_t betaGamma = ptot/gMC->TrackMass();
1183 Int_t pid=gMC->TrackPid();
1184 if((pid==kElectron || pid==kPositron) && ptot > 0.002)
1186 pp = kprim*1.58; // electrons above 20 MeV/c are on the plateau!
1191 betaGamma = TMath::Max(betaGamma,(Float_t)7.e-3); // protection against too small bg
1192 pp=kprim*BetheBloch(betaGamma);
1194 if(TMath::Abs(charge) > 1.) pp *= (charge*charge);
1197 Double_t rnd = gMC->GetRandom()->Rndm();
1199 gMC->SetMaxStep(-TMath::Log(rnd)/pp);
1204 //_____________________________________________________________________________
1205 Float_t AliTPCv2::BetheBloch(Float_t bg)
1208 // Bethe-Bloch energy loss formula
1210 const Double_t kp1=0.76176e-1;
1211 const Double_t kp2=10.632;
1212 const Double_t kp3=0.13279e-4;
1213 const Double_t kp4=1.8631;
1214 const Double_t kp5=1.9479;
1216 Double_t dbg = (Double_t) bg;
1218 Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg);
1220 Double_t aa = TMath::Power(beta,kp4);
1221 Double_t bb = TMath::Power(1./dbg,kp5);
1223 bb=TMath::Log(kp3+bb);
1225 return ((Float_t)((kp2-aa-bb)*kp1/aa));