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 3 -- detailed TPC and slow simulation //
25 <img src="picts/AliTPCv3Class.gif">
30 ///////////////////////////////////////////////////////////////////////////////
34 #include <TInterpreter.h>
35 #include <TLorentzVector.h>
37 #include <TVirtualMC.h>
44 #include "AliMathBase.h"
45 #include "AliTPCDigitsArray.h"
46 #include "AliTPCParam.h"
47 #include "AliTPCParamSR.h"
48 #include "AliTPCTrackHitsV2.h"
51 #include "TGeoManager.h"
52 #include "TGeoVolume.h"
58 #include "TGeoCompositeShape.h"
64 //_____________________________________________________________________________
66 AliTPCv3::AliTPCv3():AliTPC(),fIdSens(0)
73 //_____________________________________________________________________________
74 AliTPCv3::AliTPCv3(const char *name, const char *title) :
75 AliTPC(name, title), fIdSens(0)
78 // Standard constructor for Time Projection Chamber version 3
81 SetBufferSize(128000);
84 fTPCParam->Write(fTPCParam->GetTitle());
89 //_____________________________________________________________________________
90 void AliTPCv3::CreateGeometry()
93 // Creation of the TPC coarse geometry (version 3)
94 // The whole drift volume is sensitive
95 // Origin Marek Kowalski Cracow
99 <img src="picts/AliTPCgif">
104 <img src="picts/AliTPCv3Tree.gif">
107 //----------------------------------------------------------
108 // This geometry is written using TGeo class
109 // Firstly the shapes are defined, and only then the volumes
110 // What is recognized by the MC are volumes
111 //----------------------------------------------------------
113 // tpc - this will be the mother volume
117 // here I define a volume TPC
118 // retrive the medium name with "TPC_" as a leading string
120 TGeoPcon *tpc = new TGeoPcon(0.,360.,30); //30 sections
122 tpc->DefineSection(0,-289.6,77.,278.);
123 tpc->DefineSection(1,-262.1,77.,278.);
125 tpc->DefineSection(2,-262.1,83.1,278.);
126 tpc->DefineSection(3,-260.,83.1,278.);
128 tpc->DefineSection(4,-260.,70.,278.);
129 tpc->DefineSection(5,-259.6,70.,278.);
131 tpc->DefineSection(6,-259.6,68.1,278.);
132 tpc->DefineSection(7,-253.6,68.1,278.);
134 tpc->DefineSection(8,-253.6,67.88,278.);//hs
135 tpc->DefineSection(9,-74.0,60.68,278.);// hs
137 tpc->DefineSection(10,-74.0,60.1,278.);
138 tpc->DefineSection(11,-73.3,60.1,278.);
140 tpc->DefineSection(12,-73.3,56.9,278.);
141 tpc->DefineSection(13,-68.5,56.9,278.);
143 tpc->DefineSection(14,-68.5,60.,278.);
144 tpc->DefineSection(15,-64.7,60.,278.);
146 tpc->DefineSection(16,-64.7,56.9,278.);
147 tpc->DefineSection(17,73.3,56.9,278.);
149 tpc->DefineSection(18,73.3,60.1,278.);
150 tpc->DefineSection(19,74.0,60.1,278.);
152 tpc->DefineSection(20,74.0,60.68,278.);// hs
153 tpc->DefineSection(21,253.6,65.38,278.);// hs
155 tpc->DefineSection(22,253.6,65.6,278.);
156 tpc->DefineSection(23,259.6,65.6,278.);
158 tpc->DefineSection(24,259.6,70.0,278.);
159 tpc->DefineSection(25,260.,70.0,278.);
161 tpc->DefineSection(26,260.,83.1,278.);
162 tpc->DefineSection(27,262.1,83.1,278.);
164 tpc->DefineSection(28,262.1,77.,278);
165 tpc->DefineSection(29,289.6,77.,278.);
168 TGeoMedium *m1 = gGeoManager->GetMedium("TPC_Air");
169 TGeoVolume *v1 = new TGeoVolume("TPC_M",tpc,m1);
171 // drift volume - sensitive volume, extended beyond the
172 // endcaps, because of the alignment
174 TGeoPcon *dvol = new TGeoPcon(0.,360.,6);
175 dvol->DefineSection(0,-260.,74.5,264.4);
176 dvol->DefineSection(1,-253.6,74.5,264.4);
178 dvol->DefineSection(2,-253.6,76.6774,258.);
179 dvol->DefineSection(3,253.6,76.6774,258.);
181 dvol->DefineSection(4,253.6,74.5,264.4);
182 dvol->DefineSection(5,260.,74.5,264.4);
184 TGeoMedium *m5 = gGeoManager->GetMedium("TPC_DriftGas2");
185 TGeoVolume *v9 = new TGeoVolume("TPC_Drift",dvol,m5);
191 TGeoPcon *tpco = new TGeoPcon(0.,360.,6); //insulator
193 tpco->DefineSection(0,-256.6,264.8,278.);
194 tpco->DefineSection(1,-253.6,264.8,278.);
196 tpco->DefineSection(2,-253.6,258.,278.);
197 tpco->DefineSection(3,250.6,258.,278.);
199 tpco->DefineSection(4,250.6,258.,275.5);
200 tpco->DefineSection(5,253.6,258.,275.5);
202 TGeoMedium *m2 = gGeoManager->GetMedium("TPC_CO2");
203 TGeoVolume *v2 = new TGeoVolume("TPC_OI",tpco,m2);
205 // outer containment vessel
207 TGeoPcon *tocv = new TGeoPcon(0.,360.,6); // containment vessel
209 tocv->DefineSection(0,-256.6,264.8,278.);
210 tocv->DefineSection(1,-253.6,264.8,278.);
212 tocv->DefineSection(2,-253.6,274.8124,278.);
213 tocv->DefineSection(3,247.6,274.8124,278.);
215 tocv->DefineSection(4,247.6,270.4,278.);
216 tocv->DefineSection(5,250.6,270.4,278.);
218 TGeoMedium *m3 = gGeoManager->GetMedium("TPC_Al");
219 TGeoVolume *v3 = new TGeoVolume("TPC_OCV",tocv,m3);
221 TGeoTube *to1 = new TGeoTube(274.8174,277.995,252.1); //epoxy
222 TGeoTube *to2 = new TGeoTube(274.8274,277.985,252.1); //tedlar
223 TGeoTube *to3 = new TGeoTube(274.8312,277.9812,252.1);//prepreg2
224 TGeoTube *to4 = new TGeoTube(274.9062,277.9062,252.1);//nomex
226 TGeoMedium *sm1 = gGeoManager->GetMedium("TPC_Epoxy");
227 TGeoMedium *sm2 = gGeoManager->GetMedium("TPC_Tedlar");
228 TGeoMedium *sm3 = gGeoManager->GetMedium("TPC_Prepreg2");
229 TGeoMedium *sm4 = gGeoManager->GetMedium("TPC_Nomex");
231 TGeoVolume *tov1 = new TGeoVolume("TPC_OCV1",to1,sm1);
232 TGeoVolume *tov2 = new TGeoVolume("TPC_OCV2",to2,sm2);
233 TGeoVolume *tov3 = new TGeoVolume("TPC_OCV3",to3,sm3);
234 TGeoVolume *tov4 = new TGeoVolume("TPC_OCV4",to4,sm4);
236 TGeoMedium *mhs = gGeoManager->GetMedium("TPC_Steel");
237 TGeoMedium *m12 = gGeoManager->GetMedium("TPC_Water");
238 //-------------------------------------------------------
239 // Tpc Outer Field Cage
240 // daughters - composite (sandwich)
241 //-------------------------------------------------------
243 TGeoPcon *tofc = new TGeoPcon(0.,360.,6);
245 tofc->DefineSection(0,-253.6,258.,269.6);
246 tofc->DefineSection(1,-250.6,258.,269.6);
248 tofc->DefineSection(2,-250.6,258.,260.0676);
249 tofc->DefineSection(3,250.6,258.,260.0676);
251 tofc->DefineSection(4,250.6,258.,275.5);
252 tofc->DefineSection(5,253.6,258.,275.5);
254 TGeoVolume *v4 = new TGeoVolume("TPC_TOFC",tofc,m3);
256 TGeoTube *tf1 = new TGeoTube(258.0,260.0676,252.1); //tedlar
257 TGeoTube *tf2 = new TGeoTube(258.0038,260.0638,252.1); //prepreg3
258 TGeoTube *tf3 = new TGeoTube(258.0338,260.0338,252.1);//nomex
260 TGeoMedium *sm5 = gGeoManager->GetMedium("TPC_Prepreg3");
262 TGeoVolume *tf1v = new TGeoVolume("TPC_OFC1",tf1,sm2);
263 TGeoVolume *tf2v = new TGeoVolume("TPC_OFC2",tf2,sm5);
264 TGeoVolume *tf3v = new TGeoVolume("TPC_OFC3",tf3,sm4);
266 // outer part - positioning
268 tov1->AddNode(tov2,1); tov2->AddNode(tov3,1); tov3->AddNode(tov4,1);
270 tf1v->AddNode(tf2v,1); tf2v->AddNode(tf3v,1);
272 v3->AddNode(tov1,1,new TGeoTranslation(0.,0.,-1.5)); v4->AddNode(tf1v,1);
274 v2->AddNode(v3,1); v2->AddNode(v4,1);
277 //-----------------------------------------------------------
284 //--------------------------------------------------------------------
285 // Tpc Inner INsulator (CO2)
286 // the cones, the central drum and the inner f.c. sandwich with a piece
287 // of the flane will be placed in the TPC
288 //--------------------------------------------------------------------
289 TGeoPcon *tpci = new TGeoPcon(0.,360.,4);
291 tpci->DefineSection(0,-253.6,68.4,76.6774);
292 tpci->DefineSection(1,-74.0,61.2,76.6774);
294 tpci->DefineSection(2,74.0,61.2,76.6774);
296 tpci->DefineSection(3,253.6,65.9,76.6774);
298 TGeoVolume *v5 = new TGeoVolume("TPC_INI",tpci,m2);
300 // now the inner field cage - only part of flanges (2 copies)
302 TGeoTube *tif1 = new TGeoTube(69.9,76.6774,1.5);
303 TGeoVolume *v6 = new TGeoVolume("TPC_IFC1",tif1,m3);
305 //---------------------------------------------------------
306 // Tpc Inner Containment vessel - Muon side
307 //---------------------------------------------------------
308 TGeoPcon *tcms = new TGeoPcon(0.,360.,10);
310 tcms->DefineSection(0,-259.1,68.1,74.2);
311 tcms->DefineSection(1,-253.6,68.1,74.2);
313 tcms->DefineSection(2,-253.6,68.1,68.4);
314 tcms->DefineSection(3,-74.0,60.9,61.2);
316 tcms->DefineSection(4,-74.0,60.1,61.2);
317 tcms->DefineSection(5,-73.3,60.1,61.2);
319 tcms->DefineSection(6,-73.3,56.9,61.2);
320 tcms->DefineSection(7,-73.0,56.9,61.2);
322 tcms->DefineSection(8,-73.0,56.9,58.8);
323 tcms->DefineSection(9,-71.3,56.9,58.8);
325 TGeoVolume *v7 = new TGeoVolume("TPC_ICVM",tcms,m3);
326 //------------------------------------------------
327 // Heat screen muon side
328 //------------------------------------------------
330 TGeoCone *thsm = new TGeoCone(89.8,67.88,68.1,60.68,60.9);
331 TGeoCone *thsmw = new TGeoCone(89.8,67.94,68.04,60.74,60.84);
332 TGeoVolume *hvsm = new TGeoVolume("TPC_HSM",thsm,mhs); //steel
333 TGeoVolume *hvsmw = new TGeoVolume("TPC_HSMW",thsmw,m12); //water
334 // assembly heat screen muon
335 hvsm->AddNode(hvsmw,1);
336 //-----------------------------------------------
337 // inner containment vessel - shaft side
338 //-----------------------------------------------
339 TGeoPcon *tcss = new TGeoPcon(0.,360.,10);
341 tcss->DefineSection(0,71.3,56.9,58.8);
342 tcss->DefineSection(1,73.0,56.9,58.8);
344 tcss->DefineSection(2,73.0,56.9,61.2);
345 tcss->DefineSection(3,73.3,56.9,61.2);
347 tcss->DefineSection(4,73.3,60.1,61.2);
348 tcss->DefineSection(5,74.0,60.1,61.2);
350 tcss->DefineSection(6,74.0,60.9,61.2);
351 tcss->DefineSection(7,253.6,65.6,65.9);
353 tcss->DefineSection(8,253.6,65.6,74.2);
354 tcss->DefineSection(9,258.1,65.6,74.2);
356 TGeoVolume *v8 = new TGeoVolume("TPC_ICVS",tcss,m3);
357 //-------------------------------------------------
358 // Heat screen shaft side
359 //--------------------------------------------------
360 TGeoCone *thss = new TGeoCone(89.8,60.68,60.9,65.38,65.6);
361 TGeoCone *thssw = new TGeoCone(89.8,60.74,60.84,65.44,65.54);
362 TGeoVolume *hvss = new TGeoVolume("TPC_HSS",thss,mhs); //steel
363 TGeoVolume *hvssw = new TGeoVolume("TPC_HSSW",thssw,m12); //water
364 //assembly heat screen shaft
365 hvss->AddNode(hvssw,1);
366 //-----------------------------------------------
368 // define 4 parts and make an assembly
369 //-----------------------------------------------
370 // part1 - Al - 2 copies
371 TGeoTube *t1 = new TGeoTube(76.6774,78.845,0.75);
372 TGeoVolume *tv1 = new TGeoVolume("TPC_IFC2",t1,m3);
373 // sandwich - outermost parts - 2 copies
374 TGeoTube *t2 = new TGeoTube(76.6774,78.845,74.175); // tedlar 38 microns
375 TGeoTube *t3 = new TGeoTube(76.6812,78.8412,74.175); // prepreg2 500 microns
376 TGeoTube *t4 = new TGeoTube(76.7312,78.7912,74.175); // prepreg3 300 microns
377 TGeoTube *t5 = new TGeoTube(76.7612,78.7612,74.175); // nomex 2 cm
379 TGeoVolume *tv2 = new TGeoVolume("TPC_IFC3",t2,sm2);
380 TGeoVolume *tv3 = new TGeoVolume("TPC_IFC4",t3,sm3);
381 TGeoVolume *tv4 = new TGeoVolume("TPC_IFC5",t4,sm5);
382 TGeoVolume *tv5 = new TGeoVolume("TPC_IFC6",t5,sm4);
384 // middle parts - 2 copies
385 TGeoTube *t6 = new TGeoTube(76.6774,78.795,5.); // tedlar 38 microns
386 TGeoTube *t7 = new TGeoTube(76.6812,78.7912,5.); // prepreg2 250 microns
387 TGeoTube *t8 = new TGeoTube(76.7062,78.7662,5.); // prepreg3 300 microns
388 TGeoTube *t9 = new TGeoTube(76.7362,78.7362,5.); // nomex 2 cm
390 TGeoVolume *tv6 = new TGeoVolume("TPC_IFC7",t6,sm2);
391 TGeoVolume *tv7 = new TGeoVolume("TPC_IFC8",t7,sm3);
392 TGeoVolume *tv8 = new TGeoVolume("TPC_IFC9",t8,sm5);
393 TGeoVolume *tv9 = new TGeoVolume("TPC_IFC10",t9,sm4);
394 // central part - 1 copy
395 TGeoTube *t10 = new TGeoTube(76.6774,78.745,93.75); // tedlar 38 microns
396 TGeoTube *t11 = new TGeoTube(76.6812,78.7412,93.75); // prepreg3 300 microns
397 TGeoTube *t12 = new TGeoTube(76.7112,78.7112,93.75); // nomex 2 cm
399 TGeoVolume *tv10 = new TGeoVolume("TPC_IFC11",t10,sm2);
400 TGeoVolume *tv11 = new TGeoVolume("TPC_IFC12",t11,sm5);
401 TGeoVolume *tv12 = new TGeoVolume("TPC_IFC13",t12,sm4);
403 // inner part - positioning
405 // creating a sandwich
406 tv2->AddNode(tv3,1); tv3->AddNode(tv4,1); tv4->AddNode(tv5,1);
408 tv6->AddNode(tv7,1); tv7->AddNode(tv8,1); tv8->AddNode(tv9,1);
410 tv10->AddNode(tv11,1); tv11->AddNode(tv12,1);
412 TGeoVolumeAssembly *tv100 = new TGeoVolumeAssembly("TPC_IFC");
414 tv100->AddNode(tv10,1);
415 tv100->AddNode(tv6,1,new TGeoTranslation(0.,0.,-98.75));
416 tv100->AddNode(tv6,2,new TGeoTranslation(0.,0.,98.75));
417 tv100->AddNode(tv2,1,new TGeoTranslation(0.,0.,-177.925));
418 tv100->AddNode(tv2,2,new TGeoTranslation(0.,0.,177.925));
419 tv100->AddNode(tv1,1,new TGeoTranslation(0.,0.,-252.85));
420 tv100->AddNode(tv1,2,new TGeoTranslation(0.,0.,252.85));
422 v5->AddNode(v6,1, new TGeoTranslation(0.,0.,-252.1));
423 v5->AddNode(v6,2, new TGeoTranslation(0.,0.,252.1));
424 v1->AddNode(v5,1); v1->AddNode(v7,1); v1->AddNode(v8,1);
425 v1->AddNode(hvsm,1,new TGeoTranslation(0.,0.,-163.8));
426 v1->AddNode(hvss,1,new TGeoTranslation(0.,0.,163.8));
427 v9->AddNode(tv100,1);
433 TGeoPcon *cfl = new TGeoPcon(0.,360.,6);
434 cfl->DefineSection(0,-71.1,59.7,61.2);
435 cfl->DefineSection(1,-68.6,59.7,61.2);
437 cfl->DefineSection(2,-68.6,60.6324,61.2);
438 cfl->DefineSection(3,68.6,60.6324,61.2);
440 cfl->DefineSection(4,68.6,59.7,61.2);
441 cfl->DefineSection(5,71.1,59.7,61.2);
443 TGeoVolume *cflv = new TGeoVolume("TPC_CDR",cfl,m3);
445 TGeoTube *cd1 = new TGeoTube(60.6424,61.19,71.1);
446 TGeoTube *cd2 = new TGeoTube(60.6462,61.1862,71.1);
447 TGeoTube *cd3 = new TGeoTube(60.6662,61.1662,71.1);
449 TGeoMedium *sm6 = gGeoManager->GetMedium("TPC_Prepreg1");
450 TGeoVolume *cd1v = new TGeoVolume("TPC_CDR1",cd1,sm2); //tedlar
451 TGeoVolume *cd2v = new TGeoVolume("TPC_CDR2",cd2,sm6);// prepreg1
452 TGeoVolume *cd3v = new TGeoVolume("TPC_CDR3",cd3,sm4); //nomex
454 // seals for central drum 2 copies
456 TGeoTube *cs = new TGeoTube(56.9,61.2,0.1);
457 TGeoMedium *sm7 = gGeoManager->GetMedium("TPC_Mylar");
458 TGeoVolume *csv = new TGeoVolume("TPC_CDRS",cs,sm7);
459 v1->AddNode(csv,1,new TGeoTranslation(0.,0.,-71.2));
460 v1->AddNode(csv,2,new TGeoTranslation(0.,0.,71.2));
463 TGeoPcon *se = new TGeoPcon(0.,360.,6);
464 se->DefineSection(0,-72.8,59.7,61.2);
465 se->DefineSection(1,-72.3,59.7,61.2);
467 se->DefineSection(2,-72.3,58.85,61.2);
468 se->DefineSection(3,-71.6,58.85,61.2);
470 se->DefineSection(4,-71.6,59.7,61.2);
471 se->DefineSection(5,-71.3,59.7,61.2);
473 TGeoVolume *sev = new TGeoVolume("TPC_CDCE",se,m3);
475 TGeoTube *si = new TGeoTube(56.9,58.8,1.);
476 TGeoVolume *siv = new TGeoVolume("TPC_CDCI",si,m3);
478 // define reflection matrix
480 TGeoRotation *ref = new TGeoRotation("ref",90.,0.,90.,90.,180.,0.);
482 cd1v->AddNode(cd2v,1); cd2v->AddNode(cd3v,1); cflv->AddNode(cd1v,1);
484 v1->AddNode(siv,1,new TGeoTranslation(0.,0.,-69.9));
485 v1->AddNode(siv,2,new TGeoTranslation(0.,0.,69.9));
486 v1->AddNode(sev,1); v1->AddNode(sev,2,ref); v1->AddNode(cflv,1);
488 // central membrane - 2 rings and a mylar membrane - assembly
490 TGeoTube *ih = new TGeoTube(81.05,84.05,0.3);
491 TGeoTube *oh = new TGeoTube(250.,256.,.5);
492 TGeoTube *mem = new TGeoTube(84.05,250,0.01);
493 TGeoVolume *ihv = new TGeoVolume("TPC_IHVH",ih,m3);
494 TGeoVolume *ohv = new TGeoVolume("TPC_OHVH",oh,m3);
495 TGeoVolume *memv = new TGeoVolume("TPC_HV",mem,sm7);
497 TGeoVolumeAssembly *cm = new TGeoVolumeAssembly("TPC_HVMEM");
503 // end caps - they are make as an assembly of single segments
504 // containing both readout chambers
506 Double_t openingAngle = 10.*TMath::DegToRad();
507 Double_t thick=1.5; // rib
508 Double_t shift = thick/TMath::Sin(openingAngle);
510 Double_t lowEdge = 86.3; // hole in the wheel
511 Double_t upEdge = 240.4; // hole in the wheel
513 new TGeoTubeSeg("sec",74.5,264.4,3.,0.,20.);
515 TGeoPgon *hole = new TGeoPgon("hole",0.,20.,1,4);
517 hole->DefineSection(0,-3.5,lowEdge-shift,upEdge-shift);
518 hole->DefineSection(1,-1.5,lowEdge-shift,upEdge-shift);
520 hole->DefineSection(2,-1.5,lowEdge-shift,upEdge+3.-shift);
521 hole->DefineSection(3,3.5,lowEdge-shift,upEdge+3.-shift);
523 Double_t ys = shift*TMath::Sin(openingAngle);
524 Double_t xs = shift*TMath::Cos(openingAngle);
525 TGeoTranslation *tr = new TGeoTranslation("tr",xs,ys,0.);
526 tr->RegisterYourself();
527 TGeoCompositeShape *chamber = new TGeoCompositeShape("sec-hole:tr");
528 TGeoVolume *sv = new TGeoVolume("TPC_WSEG",chamber,m3);
529 TGeoPgon *bar = new TGeoPgon("bar",0.,20.,1,2);
530 bar->DefineSection(0,-3.,131.5-shift,136.5-shift);
531 bar->DefineSection(1,1.5,131.5-shift,136.5-shift);
532 TGeoVolume *barv = new TGeoVolume("TPC_WBAR",bar,m3);
533 TGeoVolumeAssembly *ch = new TGeoVolumeAssembly("TPC_WCH");//empty segment
535 ch->AddNode(sv,1); ch->AddNode(barv,1,tr);
541 TGeoTrd1 *ibody = new TGeoTrd1(13.8742,21.3328,4.29,21.15);
542 TGeoVolume *ibdv = new TGeoVolume("TPC_IROCB",ibody,m3);
544 TGeoTrd1 *emp = new TGeoTrd1(12.3742,19.8328,3.99,19.65);
545 TGeoVolume *empv = new TGeoVolume("TPC_IROCE",emp,m1);
546 ibdv->AddNode(empv,1,new TGeoTranslation(0.,-0.3,0.));
548 Double_t tga = (19.8328-12.3742)/39.3;
550 xmin = 9.55*tga+12.3742;
551 xmax = 9.95*tga+12.3742;
552 TGeoTrd1 *ib1 = new TGeoTrd1(xmin,xmax,3.29,0.2);
553 TGeoVolume *ib1v = new TGeoVolume("TPC_IRB1",ib1,m3);
554 empv->AddNode(ib1v,1,new TGeoTranslation("tt1",0.,0.7,-9.9));
555 xmin=19.4*tga+12.3742;
556 xmax=19.9*tga+12.3742;
557 TGeoTrd1 *ib2 = new TGeoTrd1(xmin,xmax,3.29,0.25);
558 TGeoVolume *ib2v = new TGeoVolume("TPC_TRB2",ib2,m3);
559 empv->AddNode(ib2v,1,new TGeoTranslation(0.,0.7,0.));
560 xmin=29.35*tga+12.3742;
561 xmax=29.75*tga+12.3742;
562 TGeoTrd1 *ib3 = new TGeoTrd1(xmin,xmax,3.29,0.2);
563 TGeoVolume *ib3v = new TGeoVolume("TPC_IRB3",ib3,m3);
564 empv->AddNode(ib3v,1,new TGeoTranslation(0.,0.7,9.9));
566 // holes for connectors
568 TGeoBBox *conn = new TGeoBBox(0.4,0.3,4.675); // identical for iroc and oroc
569 TGeoVolume *connv = new TGeoVolume("TPC_RCCON",conn,m1);
570 TString fileName(gSystem->Getenv("ALICE_ROOT"));
571 fileName += "/TPC/conn_iroc.dat";
573 in.open(fileName.Data(), ios_base::in); // asci file
574 for(Int_t i =0;i<86;i++){
579 TGeoRotation *rrr = new TGeoRotation();
581 TGeoCombiTrans *trans = new TGeoCombiTrans("trans",x,y,z,rrr);
582 ibdv->AddNode(connv,i+1,trans);
586 new TGeoTrd1("icap",14.5974,23.3521,1.19,24.825);
588 new TGeoTrd1("ihole",13.8742,21.3328,1.2,21.15);
589 TGeoTranslation *tr1 = new TGeoTranslation("tr1",0.,0.,1.725);
590 tr1->RegisterYourself();
591 TGeoCompositeShape *ic = new TGeoCompositeShape("icap-ihole:tr1");
592 TGeoVolume *icv = new TGeoVolume("TPC_IRCAP",ic,m3);
594 // pad plane and wire fixations
596 TGeoTrd1 *pp = new TGeoTrd1(14.5974,23.3521,0.3,24.825); //pad+iso
597 TGeoMedium *m4 = gGeoManager->GetMedium("TPC_G10");
598 TGeoVolume *ppv = new TGeoVolume("TPC_IRPP",pp,m4);
599 TGeoPara *f1 = new TGeoPara(.6,.5,24.825,0.,-10.,0.);
600 TGeoVolume *f1v = new TGeoVolume("TPC_IRF1",f1,m4);
601 TGeoPara *f2 = new TGeoPara(.6,.5,24.825,0.,10.,0.);
602 TGeoVolume *f2v = new TGeoVolume("TPC_IRF2",f2,m4);
604 TGeoVolumeAssembly *iroc = new TGeoVolumeAssembly("TPC_IROC");
606 iroc->AddNode(ibdv,1);
607 iroc->AddNode(icv,1,new TGeoTranslation(0.,3.1,-1.725));
608 iroc->AddNode(ppv,1,new TGeoTranslation(0.,4.59,-1.725));
609 tga =(23.3521-14.5974)/49.65;
610 Double_t xx = 24.825*tga+14.5974-0.6;
611 iroc->AddNode(f1v,1,new TGeoTranslation(-xx,5.39,-1.725));
612 iroc->AddNode(f2v,1,new TGeoTranslation(xx,5.39,-1.725));
616 TGeoTrd1 *obody = new TGeoTrd1(22.2938,40.5084,4.19,51.65);
617 TGeoVolume *obdv = new TGeoVolume("TPC_OROCB",obody,m3);
618 TGeoTrd1 *oemp = new TGeoTrd1(20.2938,38.5084,3.89,49.65);
619 TGeoVolume *oempv = new TGeoVolume("TPC_OROCE",oemp,m1);
620 obdv->AddNode(oempv,1,new TGeoTranslation(0.,-0.3,0.));
622 tga=(38.5084-20.2938)/99.3;
623 xmin=tga*10.2+20.2938;
624 xmax=tga*10.6+20.2938;
625 TGeoTrd1 *ob1 = new TGeoTrd1(xmin,xmax,2.915,0.2);
626 TGeoVolume *ob1v = new TGeoVolume("TPC_ORB1",ob1,m3);
628 xmin=22.55*tga+20.2938;
629 xmax=24.15*tga+20.2938;
630 TGeoTrd1 *ob2 = new TGeoTrd1(xmin,xmax,2.915,0.8);
631 TGeoVolume *ob2v = new TGeoVolume("TPC_ORB2",ob2,m3);
633 xmin=36.1*tga+20.2938;
634 xmax=36.5*tga+20.2938;
635 TGeoTrd1 *ob3 = new TGeoTrd1(xmin,xmax,2.915,0.2);
636 TGeoVolume *ob3v = new TGeoVolume("TPC_ORB3",ob3,m3);
638 xmin=49.0*tga+20.2938;
639 xmax=50.6*tga+20.2938;
640 TGeoTrd1 *ob4 = new TGeoTrd1(xmin,xmax,2.915,0.8);
641 TGeoVolume *ob4v = new TGeoVolume("TPC_ORB4",ob4,m3);
643 xmin=63.6*tga+20.2938;
644 xmax=64.0*tga+20.2938;
645 TGeoTrd1 *ob5 = new TGeoTrd1(xmin,xmax,2.915,0.2);
646 TGeoVolume *ob5v = new TGeoVolume("TPC_ORB5",ob5,m3);
648 xmin=75.5*tga+20.2938;
649 xmax=77.15*tga+20.2938;
650 TGeoTrd1 *ob6 = new TGeoTrd1(xmin,xmax,2.915,0.8);
651 TGeoVolume *ob6v = new TGeoVolume("TPC_ORB6",ob6,m3);
653 xmin=88.7*tga+20.2938;
654 xmax=89.1*tga+20.2938;
655 TGeoTrd1 *ob7 = new TGeoTrd1(xmin,xmax,2.915,0.2);
656 TGeoVolume *ob7v = new TGeoVolume("TPC_ORB7",ob7,m3);
658 oempv->AddNode(ob1v,1,new TGeoTranslation(0.,0.975,-39.25));
659 oempv->AddNode(ob2v,1,new TGeoTranslation(0.,0.975,-26.3));
660 oempv->AddNode(ob3v,1,new TGeoTranslation(0.,0.975,-13.35));
661 oempv->AddNode(ob4v,1,new TGeoTranslation(0.,0.975,0.15));
662 oempv->AddNode(ob5v,1,new TGeoTranslation(0.,0.975,14.15));
663 oempv->AddNode(ob6v,1,new TGeoTranslation(0.,0.975,26.7));
664 oempv->AddNode(ob7v,1,new TGeoTranslation(0.,0.975,39.25));
666 TGeoBBox *ob8 = new TGeoBBox(0.8,2.915,5.1);
667 TGeoBBox *ob9 = new TGeoBBox(0.8,2.915,5.975);
668 TGeoBBox *ob10 = new TGeoBBox(0.8,2.915,5.775);
669 TGeoBBox *ob11 = new TGeoBBox(0.8,2.915,6.25);
670 TGeoBBox *ob12 = new TGeoBBox(0.8,2.915,6.5);
672 TGeoVolume *ob8v = new TGeoVolume("TPC_ORB8",ob8,m3);
673 TGeoVolume *ob9v = new TGeoVolume("TPC_ORB9",ob9,m3);
674 TGeoVolume *ob10v = new TGeoVolume("TPC_ORB10",ob10,m3);
675 TGeoVolume *ob11v = new TGeoVolume("TPC_ORB11",ob11,m3);
676 TGeoVolume *ob12v = new TGeoVolume("TPC_ORB12",ob12,m3);
678 oempv->AddNode(ob8v,1,new TGeoTranslation(0.,0.975,-44.55));
679 oempv->AddNode(ob8v,2,new TGeoTranslation(0.,0.975,44.55));
680 oempv->AddNode(ob9v,1,new TGeoTranslation(0.,0.975,-33.075));
681 oempv->AddNode(ob9v,2,new TGeoTranslation(0.,0.975,-19.525));
682 oempv->AddNode(ob10v,1,new TGeoTranslation(0.,0.975,20.125));
683 oempv->AddNode(ob10v,2,new TGeoTranslation(0.,0.975,33.275));
684 oempv->AddNode(ob11v,1,new TGeoTranslation(0.,0.975,-6.9));
685 oempv->AddNode(ob12v,1,new TGeoTranslation(0.,0.975,7.45));
687 // holes for connectors
689 fileName = gSystem->Getenv("ALICE_ROOT");
690 fileName += "/TPC/conn_oroc.dat";
691 in.open(fileName.Data(), ios_base::in); // asci file
692 for(Int_t i =0;i<78;i++){
695 Double_t x1,z1,x2,z2;
697 Double_t xr = 4.7*TMath::Sin(ang*TMath::DegToRad());
698 Double_t zr = 4.7*TMath::Cos(ang*TMath::DegToRad());
700 x1=xr+x; x2=-xr+x; z1=zr+z; z2 = -zr+z;
702 TGeoRotation *rr = new TGeoRotation();
706 TGeoCombiTrans *trans1 = new TGeoCombiTrans("trans1",x1,y,z1,rr);
707 TGeoCombiTrans *trans2 = new TGeoCombiTrans("trans2",x2,y,z2,rr);
708 obdv->AddNode(connv,i+1,trans1);
709 obdv->AddNode(connv,i+79,trans2);
713 new TGeoTrd1("ocap",23.3874,43.5239,1.09,57.1);
714 new TGeoTrd1("ohole",22.2938,40.5084,1.09,51.65);
715 TGeoTranslation *tr5 = new TGeoTranslation("tr5",0.,0.,-2.15);
716 tr5->RegisterYourself();
717 TGeoCompositeShape *oc = new TGeoCompositeShape("ocap-ohole:tr5");
718 TGeoVolume *ocv = new TGeoVolume("TPC_ORCAP",oc,m3);
720 // pad plane and wire fixations
722 TGeoTrd1 *opp = new TGeoTrd1(23.3874,43.5239,0.3,57.1);
723 TGeoVolume *oppv = new TGeoVolume("TPC_ORPP",opp,m4);
725 tga=(43.5239-23.3874)/114.2;
726 TGeoPara *f3 = new TGeoPara(.7,.6,57.1,0.,-10.,0.);
727 TGeoPara *f4 = new TGeoPara(.7,.6,57.1,0.,10.,0.);
728 xx = 57.1*tga+23.3874-0.7;
729 TGeoVolume *f3v = new TGeoVolume("TPC_ORF1",f3,m4);
730 TGeoVolume *f4v = new TGeoVolume("TPC_ORF2",f4,m4);
732 TGeoVolumeAssembly *oroc = new TGeoVolumeAssembly("TPC_OROC");
734 oroc->AddNode(obdv,1);
735 oroc->AddNode(ocv,1,new TGeoTranslation(0.,3.1,2.15));
736 oroc->AddNode(oppv,1,new TGeoTranslation(0.,4.49,2.15));
737 oroc->AddNode(f3v,1,new TGeoTranslation(-xx,5.39,2.15));
738 oroc->AddNode(f4v,1,new TGeoTranslation(xx,5.39,2.15));
740 // now iroc and oroc are placed into a sector...
742 TGeoVolumeAssembly *secta = new TGeoVolumeAssembly("TPC_SECT"); // a-side
743 TGeoVolumeAssembly *sectc = new TGeoVolumeAssembly("TPC_SECT"); // c-side
744 TGeoRotation rot1("rot1",90.,90.,0.);
745 TGeoRotation rot2("rot2");
747 TGeoRotation *rot = new TGeoRotation("rot");
751 x0=110.2*TMath::Cos(openingAngle);
752 y0=110.2*TMath::Sin(openingAngle);
753 TGeoCombiTrans *combi1a = new TGeoCombiTrans("combi1",x0,y0,1.09+0.195,rot); //a-side
754 TGeoCombiTrans *combi1c = new TGeoCombiTrans("combi1",x0,y0,1.09+0.222,rot); //c-side
755 x0=188.45*TMath::Cos(openingAngle);
756 y0=188.45*TMath::Sin(openingAngle);
757 TGeoCombiTrans *combi2a = new TGeoCombiTrans("combi2",x0,y0,0.99+0.195,rot); //a-side
758 TGeoCombiTrans *combi2c = new TGeoCombiTrans("combi2",x0,y0,0.99+0.222,rot); //c-side
762 secta->AddNode(ch,1);
763 secta->AddNode(iroc,1,combi1a);
764 secta->AddNode(oroc,1,combi2a);
768 sectc->AddNode(ch,1);
769 sectc->AddNode(iroc,1,combi1c);
770 sectc->AddNode(oroc,1,combi2c);
772 // now I try to make wheels...
774 TGeoVolumeAssembly *wheela = new TGeoVolumeAssembly("TPC_ENDCAP");
775 TGeoVolumeAssembly *wheelc = new TGeoVolumeAssembly("TPC_ENDCAP");
777 for(Int_t i =0;i<18;i++){
778 Double_t phi = (20.*i);
779 TGeoRotation *r = new TGeoRotation();
781 wheela->AddNode(secta,i+1,r);
782 wheelc->AddNode(sectc,i+1,r);
785 // wheels in the drift volume!
786 TGeoCombiTrans *combi3 = new TGeoCombiTrans("combi3",0.,0.,256.6,ref);
787 v9->AddNode(wheela,1,combi3);
788 v9->AddNode(wheelc,2,new TGeoTranslation(0.,0.,-256.6));
790 //_____________________________________________________________
791 // service support wheel
792 //_____________________________________________________________
793 TGeoPgon *sw = new TGeoPgon(0.,20.,1,2);
794 sw->DefineSection(0,-4.,80.5,251.75);
795 sw->DefineSection(1,4.,80.5,251.75);
796 TGeoVolume *swv = new TGeoVolume("TPC_SWSEG",sw,m3); //Al
799 shift = thick/TMath::Sin(openingAngle);
800 TGeoPgon *sh = new TGeoPgon(0.,20.,1,2);
801 sh->DefineSection(0,-4.,81.5-shift,250.75-shift);
802 sh->DefineSection(1,4.,81.5-shift,250.75-shift);
803 TGeoVolume *shv = new TGeoVolume("TPC_SWS1",sh,m1); //Air
805 TGeoMedium *m9 = gGeoManager->GetMedium("TPC_Si");
806 TGeoPgon *el = new TGeoPgon(0.,20.,1,2);
807 el->DefineSection(0,-1.872,81.5-shift,250.75-shift);
808 el->DefineSection(1,1.872,81.5-shift,250.75-shift);
809 TGeoVolume *elv = new TGeoVolume("TPC_ELEC",el,m9); //Si
813 ys = shift*TMath::Sin(openingAngle);
814 xs = shift*TMath::Cos(openingAngle);
815 swv->AddNode(shv,1,new TGeoTranslation(xs,ys,0.));
817 TGeoPgon *co = new TGeoPgon(0.,20.,1,2);
818 co->DefineSection(0,-0.5,77.,255.25);
819 co->DefineSection(1,0.5,77.,255.25);
820 TGeoVolume *cov = new TGeoVolume("TPC_SWC1",co,m3);//Al
822 TGeoPgon *coh = new TGeoPgon(0.,20.,1,2);
823 shift=4./TMath::Sin(openingAngle);
824 coh->DefineSection(0,-0.5,85.-shift,247.25-shift);
825 coh->DefineSection(1,0.5,85.-shift,247.25-shift);
827 TGeoVolume *cohv = new TGeoVolume("TPC_SWC2",coh,m1);
829 ys = shift*TMath::Sin(openingAngle);
830 xs = shift*TMath::Cos(openingAngle);
831 cov->AddNode(cohv,1,new TGeoTranslation(xs,ys,0.));
833 // Sector as an Assembly
835 TGeoVolumeAssembly *swhs = new TGeoVolumeAssembly("TPC_SSWSEC");
836 swhs->AddNode(swv,1);
837 swhs->AddNode(cov,1,new TGeoTranslation(0.,0.,-4.5));
838 swhs->AddNode(cov,2,new TGeoTranslation(0.,0.,4.5));
840 // SSW as an Assembly of sectors
842 TGeoVolumeAssembly *swheel = new TGeoVolumeAssembly("TPC_SSWHEEL");
843 for(Int_t i =0;i<18;i++){
844 Double_t phi = (20.*i);
845 TGeoRotation *r = new TGeoRotation();
847 swheel->AddNode(swhs,i+1,r);
849 v1->AddNode(swheel,1,new TGeoTranslation(0.,0.,-284.6));
850 v1->AddNode(swheel,2,new TGeoTranslation(0.,0.,284.6));
852 //----------------------------------------------------------
853 // TPc Support Rods - MAKROLON
854 //----------------------------------------------------------
855 TGeoMedium *m6=gGeoManager->GetMedium("TPC_Makrolon");
856 TGeoMedium *m7=gGeoManager->GetMedium("TPC_Cu");
857 TGeoMedium *m10 = gGeoManager->GetMedium("TPC_Alumina");
858 TGeoMedium *m11 = gGeoManager->GetMedium("TPC_Peek");
859 // upper and lower rods differ in length!
862 gGeoManager->Volume("TPC_Rod","TUBE",m6->GetId(),upar);
863 upar=new Double_t [3];
868 //HV rods - makrolon + 0.58cm (diameter) Cu
869 TGeoTube *hvr = new TGeoTube(0.,2.2,126.64);
870 TGeoTube *hvc = new TGeoTube(0.,0.29,126.64);
872 TGeoVolume *hvrv = new TGeoVolume("TPC_HV_Rod",hvr,m6);
873 TGeoVolume *hvcv = new TGeoVolume("TPC_HV_Cable",hvc,m7);
874 hvrv->AddNode(hvcv,1);
878 TGeoTube *cri = new TGeoTube(0.,0.45,126.64); //inner
879 TGeoTube *cro = new TGeoTube(0.,0.45,126.54); //outer
880 TGeoTube *cwi = new TGeoTube(0.,0.15,126.64); // water inner
881 TGeoTube *cwo = new TGeoTube(0.,0.15,126.54); // water outer
883 TGeoVolume *criv = new TGeoVolume("TPC_CR_I",cri,m10);
884 TGeoVolume *crov = new TGeoVolume("TPC_CR_O",cro,m10);
885 TGeoVolume *cwiv = new TGeoVolume("TPC_W_I",cwi,m11);
886 TGeoVolume *cwov = new TGeoVolume("TPC_W_O",cwo,m11);
888 // ceramic rod with water
890 criv->AddNode(cwiv,1);
891 crov->AddNode(cwov,1);
893 TGeoTube *pri =new TGeoTube(0.2,0.35,126.64); //inner
894 TGeoTube *pro = new TGeoTube(0.2,0.35,126.54); //outer
898 TGeoVolume *priv = new TGeoVolume("TPC_PR_I",pri,m12);
899 TGeoVolume *prov = new TGeoVolume("TPC_PR_O",pro,m12);
901 // resistor rods assembly
903 TGeoRotation *rotr = new TGeoRotation("rotr");
906 TGeoTube *rri = new TGeoTube(1.8,2.2,126.64);//inner
907 TGeoTube *rro = new TGeoTube(1.8,2.2,126.54);//inner
909 TGeoVolume *rriv = new TGeoVolume("TPC_RR_I",rri,m6);
910 TGeoVolume *rrov = new TGeoVolume("TPC_RR_O",rro,m6);
912 TGeoVolumeAssembly *rrin = new TGeoVolumeAssembly("TPC_RROD_I");
913 TGeoVolumeAssembly *rrou = new TGeoVolumeAssembly("TPC_RROD_O");
914 rrin->AddNode(rriv,1);
915 rrin->AddNode(criv,1,new TGeoTranslation(0.5,0.866, 0.));
916 rrin->AddNode(criv,2,new TGeoTranslation(0.5,-0.866, 0.));
917 rrin->AddNode(priv,1);
919 rrou->AddNode(rrov,1);
920 rrou->AddNode(crov,1,new TGeoTranslation(0.5,0.866, 0.));
921 rrou->AddNode(crov,2,new TGeoTranslation(0.5,-0.866, 0.));
922 rrou->AddNode(prov,1);
923 for(Int_t i=0;i<18;i++){
926 angle=TMath::DegToRad()*20.*(Double_t)i;
928 x=r * TMath::Cos(angle);
929 y=r * TMath::Sin(angle);
930 upar[2]=126.64; //lower
934 v9->AddNode(rrin,1,new TGeoCombiTrans(x,y,z,rotr)); //A
935 v9->AddNode(rrin,2,new TGeoCombiTrans(x,y,-z,rotr)); //C
938 gGeoManager->Node("TPC_Rod",i+1,"TPC_Drift",x,y,z,0,kTRUE,upar,3);//shaft
939 gGeoManager->Node("TPC_Rod",i+19,"TPC_Drift",x,y,-z,0,kTRUE,upar,3);//muon
945 x=r * TMath::Cos(angle);
946 y=r * TMath::Sin(angle);
947 upar[2]=126.54; //upper
950 //v9->AddNode(hvrv,1,new TGeoTranslation(x,y,z));//A-side only
951 v9->AddNode(hvrv,1,new TGeoTranslation(x,y,127.14));//A-side only
952 gGeoManager->Node("TPC_Rod",i+55,"TPC_Drift",x,y,-z,0,kTRUE,upar,3);
955 v9->AddNode(rrou,1,new TGeoCombiTrans(x,y,z,rotr)); //A
956 v9->AddNode(rrou,2,new TGeoCombiTrans(x,y,-z,rotr)); //C
960 gGeoManager->Node("TPC_Rod",i+37,"TPC_Drift",x,y,z,0,kTRUE,upar,3);
961 gGeoManager->Node("TPC_Rod",i+55,"TPC_Drift",x,y,-z,0,kTRUE,upar,3);
965 TGeoVolume *alice = gGeoManager->GetVolume("ALIC");
966 alice->AddNode(v1,1);
974 //_____________________________________________________________________________
975 void AliTPCv3::CreateMaterials()
978 // Define materials for version 2 of the Time Projection Chamber
983 AliTPC::CreateMaterials();
986 //_____________________________________________________________________________
987 void AliTPCv3::Init()
990 // Initialises version 3 of the TPC after that it has been built
992 //Int_t *idtmed = fIdtmed->GetArray();
996 fIdSens=gMC->VolId("TPC_Drift"); // drift gas as a sensitive volume
998 gMC->SetMaxNStep(-30000); // max. number of steps increased
1000 // specific energy loss is now set in galice.cuts
1002 printf("%s: *** TPC version 3 initialized***\n",ClassName());
1004 printf("%s: Maximum number of steps = %d\n",ClassName(),gMC->GetMaxNStep());
1006 // printf("*** TPC version 3 initialized ***\n");
1007 // printf("Maximum number of steps = %d\n",gMC->GetMaxNStep());
1013 //_____________________________________________________________________________
1014 void AliTPCv3::StepManager()
1017 // Called for every step in the Time Projection Chamber
1021 // parameters used for the energy loss calculations
1023 const Float_t kprim = 14.35; // number of primary collisions per 1 cm
1024 const Float_t kpoti = 20.77e-9; // first ionization potential for Ne/CO2
1025 const Float_t kwIon = 35.97e-9; // energy for the ion-electron pair creation
1028 const Float_t kbig = 1.e10;
1040 gMC->SetMaxStep(kbig);
1042 if(!gMC->IsTrackAlive()) return; // particle has disappeared
1044 Float_t charge = gMC->TrackCharge();
1046 if(TMath::Abs(charge)<=0.) return; // take only charged particles
1049 id=gMC->CurrentVolID(copy);
1052 if (id != fIdSens) return;
1055 // charged particle is in the sensitive volume
1058 if(gMC->TrackStep() > 0) {
1061 Int_t nel = (Int_t)(((gMC->Edep())-kpoti)/kwIon) + 1;
1062 nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV
1064 gMC->TrackPosition(pos);
1069 // Get also the track time for pileup simulation
1070 hits[4]=gMC->TrackTime();
1073 // check the selected side of the TPC
1076 if(fSide && fSide*hits[2]<=0.) return;
1078 hits[3]=(Float_t)nel;
1082 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(), vol,hits); //MI change
1086 // Stemax calculation for the next step
1090 gMC->TrackMomentum(mom);
1091 Float_t ptot=mom.Rho();
1092 Float_t betaGamma = ptot/gMC->TrackMass();
1094 Int_t pid=gMC->TrackPid();
1095 if((pid==kElectron || pid==kPositron) && ptot > 0.002)
1097 pp = kprim*1.58; // electrons above 20 MeV/c are on the plateau!
1101 betaGamma = TMath::Max(betaGamma,(Float_t)7.e-3);
1102 pp=kprim*AliMathBase::BetheBlochAleph(betaGamma);
1103 if(TMath::Abs(charge) > 1.) pp *= (charge*charge);
1106 Double_t rnd = gMC->GetRandom()->Rndm();
1108 gMC->SetMaxStep(-TMath::Log(rnd)/pp);