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4c039060 | 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 | /* | |
17 | $Log$ | |
cdde5b1e | 18 | Revision 1.15 1999/09/29 09:24:34 fca |
19 | Introduction of the Copyright and cvs Log | |
20 | ||
4c039060 | 21 | */ |
22 | ||
fe4da5cc | 23 | /////////////////////////////////////////////////////////////////////////////// |
24 | // // | |
25 | // Time Projection Chamber version 2 -- detailed TPC and slow simulation // | |
26 | // // | |
27 | //Begin_Html | |
28 | /* | |
1439f98e | 29 | <img src="picts/AliTPCv2Class.gif"> |
fe4da5cc | 30 | */ |
31 | //End_Html | |
32 | // // | |
33 | // // | |
34 | /////////////////////////////////////////////////////////////////////////////// | |
2a49965d | 35 | #include <stdlib.h> |
fe4da5cc | 36 | |
37 | #include <TMath.h> | |
bcac8ae4 | 38 | |
fe4da5cc | 39 | #include "AliTPCv2.h" |
bcac8ae4 | 40 | #include "AliTPCD.h" |
fe4da5cc | 41 | #include "AliRun.h" |
fe4da5cc | 42 | #include "AliConst.h" |
8c555625 | 43 | |
fe4da5cc | 44 | ClassImp(AliTPCv2) |
45 | ||
46 | //_____________________________________________________________________________ | |
47 | AliTPCv2::AliTPCv2(const char *name, const char *title) : | |
48 | AliTPC(name, title) | |
49 | { | |
50 | // | |
51 | // Standard constructor for Time Projection Chamber version 2 | |
52 | // | |
53 | fIdSens1=0; | |
54 | fIdSens2=0; | |
55 | SetBufferSize(128000); | |
56 | } | |
57 | ||
58 | //_____________________________________________________________________________ | |
59 | void AliTPCv2::CreateGeometry() | |
60 | { | |
61 | // | |
62 | // Create the geometry of Time Projection Chamber version 2 | |
63 | // | |
64 | //Begin_Html | |
65 | /* | |
1439f98e | 66 | <img src="picts/AliTPCv2.gif"> |
fe4da5cc | 67 | */ |
68 | //End_Html | |
69 | //Begin_Html | |
70 | /* | |
1439f98e | 71 | <img src="picts/AliTPCv2Tree.gif"> |
fe4da5cc | 72 | */ |
73 | //End_Html | |
74 | ||
8c555625 | 75 | AliTPCParam * fTPCParam = &(fDigParam->GetParam()); |
76 | ||
1283eee5 | 77 | Int_t *idtmed = fIdtmed->GetArray(); |
78 | ||
79 | Float_t dm[21]; | |
62a73ee5 | 80 | Int_t idrotm[120]; |
1283eee5 | 81 | |
82 | Int_t nRotMat = 0; | |
83 | ||
84 | Int_t i,ifl1,ifl2; | |
85 | ||
86 | Int_t nInnerSector = fTPCParam->GetNInnerSector()/2; | |
87 | Int_t nOuterSector = fTPCParam->GetNOuterSector()/2; | |
fe4da5cc | 88 | |
89 | // --------------------------------------------------- | |
90 | // sector specification check | |
91 | // --------------------------------------------------- | |
92 | if (fSecAL >= 0) { | |
93 | ifl1 = 0; | |
94 | ||
95 | for (i = 0; i < 6; ++i) { | |
1283eee5 | 96 | if (fSecLows[i] >= 0 && fSecLows[i] < 2*nInnerSector) { |
fe4da5cc | 97 | ifl1 = 1; |
98 | printf("*** SECTOR %d selected\n",fSecLows[i]); | |
99 | } | |
100 | } | |
101 | ||
102 | } else { | |
103 | printf("*** ALL LOWER SECTORS SELECTED ***\n"); | |
8c555625 | 104 | ifl1 = 1; |
fe4da5cc | 105 | } |
106 | ||
107 | if (fSecAU >= 0) { | |
108 | ifl2 = 0; | |
109 | ||
110 | for (i = 0; i < 12; ++i) { | |
1283eee5 | 111 | if (fSecUps[i] > 2*nInnerSector-1 && |
112 | fSecUps[i] < 2*(nInnerSector+nOuterSector)) { | |
fe4da5cc | 113 | ifl2 = 1; |
114 | printf("*** SECTOR %d selected\n",fSecUps[i]); | |
115 | } | |
116 | } | |
117 | ||
118 | } else { | |
119 | printf("*** ALL UPPER SECTORS SELECTED ***\n"); | |
8c555625 | 120 | ifl1 = 1; |
fe4da5cc | 121 | } |
122 | ||
123 | if (ifl1 == 0 && ifl2 == 0) { | |
124 | printf("*** ERROR: AT LEAST ONE SECTOR MUST BE SPECIFIED ***\n"); | |
125 | printf("!!! PROGRAM STOPPED !!!\n"); | |
126 | exit(1); | |
127 | } | |
128 | ||
129 | if ((fSecAL < 0 || fSecAU < 0) && fSens >= 0) { | |
130 | printf("** ERROR: STRIPS CANNOT BE SPECIFIED FOR ALL SECTORS **\n"); | |
131 | printf("!!! PROGRAM STOPPED !!!\n"); | |
132 | exit(1); | |
133 | } | |
1283eee5 | 134 | |
fe4da5cc | 135 | // ---------------------------------------------------- |
1283eee5 | 136 | // FIELD CAGE WITH ENDCAPS - G10 |
fe4da5cc | 137 | // THIS IS ALSO A TPC MOTHER VOLUME |
138 | // ---------------------------------------------------- | |
1283eee5 | 139 | |
fe4da5cc | 140 | dm[0] = 76.; |
141 | dm[1] = 278.; | |
142 | dm[2] = 275.; | |
1283eee5 | 143 | |
144 | gMC->Gsvolu("TPC ", "TUBE", idtmed[8], dm, 3); | |
145 | ||
146 | //----------------------------------------------------- | |
147 | // Endcap cover c-fibre 0.86% X0 | |
148 | //----------------------------------------------------- | |
149 | ||
150 | dm[0] = 78.; | |
151 | dm[1] = 258.; | |
152 | dm[2] = 0.95; | |
153 | ||
154 | gMC->Gsvolu("TPEC","TUBE",idtmed[10],dm,3); | |
155 | ||
156 | //----------------------------------------------------- | |
157 | // Drift gas , leave 2 cm at the outer radius | |
158 | // and inner raddius | |
159 | //----------------------------------------------------- | |
160 | ||
161 | dm[0] = 78.; | |
162 | dm[1] = 258.; | |
fe4da5cc | 163 | dm[2] = 250.; |
1283eee5 | 164 | |
165 | gMC->Gsvolu("TGAS", "TUBE", idtmed[3], dm, 3); | |
166 | ||
167 | //------------------------------------------------------ | |
168 | // membrane holder - carbon fiber | |
169 | //------------------------------------------------------ | |
170 | ||
171 | ||
172 | gMC->Gsvolu("TPMH","TUBE",idtmed[6],dm,0); | |
173 | ||
174 | dm[0] = 252.; | |
175 | dm[1] = 258.; | |
176 | dm[2] = 0.2; | |
177 | ||
178 | gMC->Gsposp("TPMH",1,"TGAS",0.,0.,0.,0,"ONLY",dm,3); | |
179 | ||
180 | dm[0] = 78.; | |
cdde5b1e | 181 | dm[1] = 82.; |
1283eee5 | 182 | dm[2] = 0.1; |
183 | ||
184 | gMC->Gsposp("TPMH",2,"TGAS",0.,0.,0.,0,"ONLY",dm,3); | |
185 | ||
186 | //---------------------------------------------------------- | |
187 | // HV membrane - 25 microns of mylar | |
188 | //---------------------------------------------------------- | |
189 | ||
190 | dm[0] = 82.; | |
191 | dm[1] = 252.; | |
192 | dm[2] = 0.00125; | |
193 | ||
194 | gMC->Gsvolu("TPHV","TUBE",idtmed[5],dm,3); | |
195 | ||
196 | gMC->Gspos("TPHV",1,"TGAS",0.,0.,0.,0,"ONLY"); | |
197 | ||
198 | gMC->Gspos("TGAS",1,"TPC ",0.,0.,0.,0,"ONLY"); | |
199 | ||
200 | //---------------------------------------------------------- | |
201 | // "side" gas volume, the same as the drift gas | |
202 | // the readout chambers are placed there. | |
203 | //---------------------------------------------------------- | |
204 | ||
205 | dm[0] = 78.; | |
206 | dm[1] = 258.; | |
207 | dm[2] = 0.5*(275. - 250.); | |
208 | ||
209 | gMC->Gsvolu("TPSG", "TUBE", idtmed[2], dm, 3); | |
210 | ||
211 | Float_t z_side = dm[2]; // 1/2 of the side gas thickness | |
212 | ||
213 | //----------------------------------------------------------- | |
214 | // Readout chambers , 25% of X0, I use Al as the material | |
215 | //----------------------------------------------------------- | |
216 | ||
217 | Float_t InnerOpenAngle = fTPCParam->GetInnerAngle(); | |
218 | Float_t OuterOpenAngle = fTPCParam->GetOuterAngle(); | |
219 | ||
220 | Float_t InnerAngleShift = fTPCParam->GetInnerAngleShift(); | |
221 | Float_t OuterAngleShift = fTPCParam->GetOuterAngleShift(); | |
222 | ||
223 | Float_t InSecLowEdge = fTPCParam->GetInSecLowEdge(); | |
224 | Float_t InSecUpEdge = fTPCParam->GetInSecUpEdge(); | |
225 | ||
226 | Float_t OuSecLowEdge = fTPCParam->GetOuSecLowEdge(); | |
227 | Float_t OuSecUpEdge = fTPCParam->GetOuSecUpEdge(); | |
228 | ||
229 | ||
230 | Float_t SecThick = 2.225; // Al | |
231 | ||
232 | Float_t edge = fTPCParam->GetEdge(); | |
233 | ||
234 | // S (Inner) sectors | |
235 | ||
236 | dm[0] = InSecLowEdge*TMath::Tan(0.5*InnerOpenAngle)-edge; | |
237 | dm[1] = InSecUpEdge*TMath::Tan(0.5*InnerOpenAngle)-edge; | |
238 | dm[2] = 0.5*SecThick; | |
239 | dm[3] = 0.5*(InSecUpEdge-InSecLowEdge); | |
240 | ||
241 | Float_t xCenterS = InSecLowEdge+dm[3]; | |
242 | ||
243 | gMC->Gsvolu("TRCS", "TRD1", idtmed[0], dm, 4); | |
244 | ||
245 | // L (Outer) sectors | |
246 | ||
247 | dm[0] = OuSecLowEdge*TMath::Tan(0.5*OuterOpenAngle)-edge; | |
248 | dm[1] = OuSecUpEdge*TMath::Tan(0.5*OuterOpenAngle)-edge; | |
249 | dm[2] = 0.5*SecThick; | |
250 | dm[3] = 0.5*(OuSecUpEdge-OuSecLowEdge); | |
251 | ||
252 | Float_t xCenterL = OuSecLowEdge+dm[3]; | |
253 | ||
254 | gMC->Gsvolu("TRCL", "TRD1", idtmed[0], dm, 4); | |
255 | ||
256 | Float_t z1 = -z_side + SecThick*0.5; | |
257 | ||
258 | //------------------------------------------------------------------ | |
259 | // S sectors - "gas sectors" (TRD1) | |
260 | //------------------------------------------------------------------ | |
261 | ||
262 | dm[0] = InSecLowEdge*TMath::Tan(0.5*InnerOpenAngle)-0.01; | |
263 | dm[1] = InSecUpEdge*TMath::Tan(0.5*InnerOpenAngle)-0.01; | |
264 | dm[2] = 0.5*(250. - 0.001); | |
265 | dm[3] = 0.5*(InSecUpEdge-InSecLowEdge); | |
266 | ||
267 | gMC->Gsvolu("TSGA", "TRD1", idtmed[4], dm, 4); // sensitive | |
268 | ||
fe4da5cc | 269 | // ------------------------------------------------------------- |
270 | // Only for the debugging purpose and resolution calculation | |
271 | // Sensitive strips at the pad-row center | |
272 | // ------------------------------------------------------------- | |
1283eee5 | 273 | |
274 | Int_t ns; | |
275 | ||
276 | if(fSens>=0){ | |
277 | ||
278 | Float_t r1,r2,zz; | |
279 | ||
280 | Float_t StripThick = 0.01; // 100 microns | |
281 | Float_t dead = fTPCParam->GetDeadZone(); | |
282 | ||
283 | gMC->Gsvolu("TSST", "TRD1", idtmed[4], dm, 0); | |
284 | ||
285 | dm[2] = 0.5*(250. - 0.002); | |
286 | dm[3] = 0.5 * StripThick; | |
287 | ||
288 | ||
289 | for (ns = 0; ns < fTPCParam->GetNRowLow(); ns++) { | |
290 | ||
291 | r1 = fTPCParam->GetPadRowRadiiLow(ns); | |
292 | r2 = r1 + StripThick; | |
293 | dm[0] = r1 * TMath::Tan(0.5*InnerOpenAngle) - dead; | |
294 | dm[1] = r2 * TMath::Tan(0.5*InnerOpenAngle) - dead; | |
295 | ||
296 | zz = -InSecLowEdge -0.5*(InSecUpEdge-InSecLowEdge); | |
297 | zz += r1; | |
298 | zz += dm[3]; | |
299 | ||
300 | gMC->Gsposp("TSST", ns+1, "TSGA", 0., 0., zz, 0, "ONLY", dm, 4); | |
301 | ||
fe4da5cc | 302 | |
1283eee5 | 303 | } |
304 | ||
305 | gMC->Gsord("TSGA", 3); | |
306 | ||
307 | } // if strips selected | |
308 | ||
309 | ||
310 | //----------------------------------------------------------------- | |
311 | // L sectors - "gas sectors" (PGON to avoid overlaps) | |
312 | //----------------------------------------------------------------- | |
313 | ||
314 | dm[0] = 360.*kDegrad - 0.5*OuterOpenAngle; | |
315 | dm[0] *= kRaddeg; | |
316 | dm[0] = (Float_t)TMath::Nint(dm[0]); | |
317 | ||
318 | dm[1] = OuterOpenAngle*kRaddeg; | |
319 | dm[1] = (Float_t)TMath::Nint(dm[1]); | |
320 | ||
321 | dm[2] = 1.; | |
322 | dm[3] = 4.; | |
323 | ||
324 | dm[4] = 0.002; | |
325 | dm[5] = OuSecLowEdge; | |
326 | dm[6] = 252.*TMath::Cos(0.5*OuterOpenAngle)-0.002; | |
327 | ||
328 | dm[7] = dm[4]+0.2; | |
329 | dm[8] = dm[5]; | |
330 | dm[9] = dm[6]; | |
331 | ||
332 | dm[10] = dm[7]; | |
333 | dm[11] = OuSecLowEdge; | |
334 | dm[12] = OuSecUpEdge; | |
335 | ||
336 | dm[13] = 250.; | |
337 | dm[14] = dm[11]; | |
338 | dm[15] = dm[12]; | |
339 | ||
340 | gMC->Gsvolu("TLGA","PGON",idtmed[4],dm,16); | |
8c555625 | 341 | |
fe4da5cc | 342 | if (fSens >= 0) { |
fe4da5cc | 343 | |
1283eee5 | 344 | Float_t rmax = dm[6]; |
345 | Float_t r1,r2; | |
346 | Float_t dead = fTPCParam->GetDeadZone(); | |
8c555625 | 347 | |
1283eee5 | 348 | Float_t StripThick = 0.01; // 100 microns |
8c555625 | 349 | |
1283eee5 | 350 | gMC->Gsvolu("TLST", "PGON", idtmed[4], dm, 0); |
351 | ||
352 | dm[0] = 360.*kDegrad - 0.5*OuterOpenAngle; | |
353 | dm[0] *= kRaddeg; | |
354 | dm[0] = (Float_t)TMath::Nint(dm[0]); | |
355 | ||
356 | dm[1] = OuterOpenAngle*kRaddeg; | |
357 | dm[1] = (Float_t)TMath::Nint(dm[1]); | |
8c555625 | 358 | |
fe4da5cc | 359 | dm[2] = 1.; |
1283eee5 | 360 | dm[3] = 2.; |
fe4da5cc | 361 | |
1283eee5 | 362 | dm[7] = 250.; |
fe4da5cc | 363 | |
1283eee5 | 364 | Float_t xx = dead/TMath::Tan(0.5*OuterOpenAngle); |
fe4da5cc | 365 | |
1283eee5 | 366 | for(ns=0;ns<fTPCParam->GetNRowUp();ns++){ |
fe4da5cc | 367 | |
1283eee5 | 368 | r1 = fTPCParam->GetPadRowRadiiUp(ns)-xx; |
369 | r2 = r1 + StripThick; | |
370 | ||
371 | dm[5] = r1; | |
372 | dm[6] = r2; | |
373 | ||
374 | dm[8] = r1; | |
375 | dm[9] = r2; | |
376 | ||
377 | if(r2+xx < rmax){ | |
378 | dm[4] = 0.002; | |
fe4da5cc | 379 | } |
1283eee5 | 380 | else{ |
381 | dm[4] = 0.202; | |
382 | } | |
383 | ||
384 | gMC->Gsposp("TLST",ns+1,"TLGA",xx,0.,0.,0,"ONLY",dm,10); | |
385 | ||
386 | } | |
387 | ||
62a73ee5 | 388 | gMC->Gsord("TLGA", 4); |
1283eee5 | 389 | |
390 | } // if strips selected | |
391 | ||
392 | //------------------------------------------------------------------ | |
393 | // Positioning of the S-sector readout chambers | |
394 | //------------------------------------------------------------------ | |
395 | ||
396 | Float_t zs = 0.5*(250.+0.002); | |
397 | ||
398 | Float_t theta1,theta2,theta3; | |
399 | Float_t phi1,phi2,phi3; | |
400 | Float_t alpha; | |
401 | Float_t x,y; | |
402 | ||
403 | for(ns=0;ns<nInnerSector;ns++){ | |
404 | ||
405 | phi1 = ns * InnerOpenAngle + 270.*kDegrad + InnerAngleShift; | |
406 | phi1 *= kRaddeg; // in degrees | |
407 | ||
408 | phi1 = (Float_t)TMath::Nint(phi1); | |
409 | ||
410 | if (phi1 > 360.) phi1 -= 360.; | |
fe4da5cc | 411 | |
1283eee5 | 412 | theta1 = 90.; |
413 | phi2 = 90.; | |
414 | theta2 = 180.; | |
415 | phi3 = ns * InnerOpenAngle + InnerAngleShift; | |
416 | phi3 *= kRaddeg; // in degrees | |
417 | ||
418 | phi3 = (Float_t)TMath::Nint(phi3); | |
fe4da5cc | 419 | |
1283eee5 | 420 | if(phi3 > 360.) phi3 -= 360.; |
421 | ||
422 | theta3 = 90.; | |
423 | ||
424 | alpha = phi3*kDegrad; | |
425 | ||
426 | x = xCenterS * TMath::Cos(alpha); | |
427 | y = xCenterS * TMath::Sin(alpha); | |
428 | ||
429 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
430 | ||
431 | gMC->Gspos("TRCS", ns+1, "TPSG", x, y, z1, idrotm[nRotMat], "ONLY"); | |
432 | ||
433 | if(fSecAL < 0){ | |
434 | ||
435 | //--------------------------------------------------------------- | |
436 | // position all sectors | |
437 | //--------------------------------------------------------------- | |
438 | ||
439 | gMC->Gspos("TSGA",ns+1,"TGAS",x,y,zs,idrotm[nRotMat], "ONLY"); | |
440 | gMC->Gspos("TSGA",ns+1+nInnerSector,"TGAS",x,y,-zs,idrotm[nRotMat], "ONLY"); | |
fe4da5cc | 441 | } |
1283eee5 | 442 | |
443 | else{ | |
444 | ||
445 | //--------------------------------------------------------------- | |
446 | // position selected sectors | |
447 | //--------------------------------------------------------------- | |
448 | ||
449 | for(Int_t sel=0;sel<6;sel++){ | |
450 | ||
451 | if(fSecLows[sel] == ns){ | |
452 | gMC->Gspos("TSGA", ns+1, "TGAS", x, y, zs, idrotm[nRotMat], "ONLY"); | |
453 | } | |
454 | else if(fSecLows[sel] == ns+nInnerSector){ | |
455 | gMC-> | |
456 | Gspos("TSGA",ns+1+nInnerSector,"TGAS", x, y,-zs,idrotm[nRotMat],"ONLY"); | |
457 | } | |
fe4da5cc | 458 | } |
fe4da5cc | 459 | } |
1283eee5 | 460 | |
461 | nRotMat++; | |
462 | ||
463 | } | |
fe4da5cc | 464 | |
1283eee5 | 465 | //------------------------------------------------------------------- |
466 | // Positioning of the L-sectors readout chambers | |
467 | //------------------------------------------------------------------- | |
fe4da5cc | 468 | |
1283eee5 | 469 | for(ns=0;ns<nOuterSector;ns++){ |
470 | phi1 = ns * OuterOpenAngle + 270.*kDegrad + OuterAngleShift; | |
471 | phi1 *= kRaddeg; // in degrees | |
472 | ||
473 | phi1 = (Float_t)TMath::Nint(phi1); | |
fe4da5cc | 474 | |
1283eee5 | 475 | |
476 | if (phi1 > 360.) phi1 -= 360.; | |
477 | ||
fe4da5cc | 478 | theta1 = 90.; |
1283eee5 | 479 | phi2 = 90.; |
480 | theta2 = 180.; | |
481 | phi3 = ns * OuterOpenAngle+OuterAngleShift; | |
482 | phi3 *= kRaddeg; // in degrees | |
fe4da5cc | 483 | |
1283eee5 | 484 | phi3 = (Float_t)TMath::Nint(phi3); |
fe4da5cc | 485 | |
1283eee5 | 486 | |
487 | if(phi3 > 360.) phi3 -= 360.; | |
488 | ||
489 | theta3 = 90.; | |
490 | ||
491 | alpha = phi3*kDegrad; | |
492 | ||
493 | x = xCenterL * TMath::Cos(alpha); | |
494 | y = xCenterL * TMath::Sin(alpha); | |
495 | ||
496 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
497 | ||
498 | ||
499 | gMC->Gspos("TRCL", ns+1, "TPSG", x, y, z1, idrotm[nRotMat], "ONLY"); | |
500 | ||
501 | nRotMat++; | |
502 | ||
503 | } | |
504 | ||
505 | //------------------------------------------------------------------- | |
506 | // Positioning of the L-sectors (gas sectors) | |
507 | //------------------------------------------------------------------- | |
508 | ||
509 | for(ns=0;ns<nOuterSector;ns++){ | |
510 | ||
511 | phi1 = ns*OuterOpenAngle + OuterAngleShift; | |
512 | phi1 *= kRaddeg; | |
fe4da5cc | 513 | |
1283eee5 | 514 | phi1 = (Float_t)TMath::Nint(phi1); |
515 | if(phi1>360.) phi1 -= 360.; | |
516 | ||
517 | theta1 = 90.; | |
518 | ||
519 | phi2 = 90. + phi1; | |
520 | if(phi2>360.) phi2 -= 360.; | |
521 | ||
522 | theta2 = 90.; | |
523 | ||
524 | phi3 = 0.; | |
525 | theta3 = 0.; | |
526 | ||
527 | if(fSecAU < 0) { | |
528 | ||
529 | //-------------------------------------------------------------- | |
530 | // position all sectors | |
531 | //-------------------------------------------------------------- | |
532 | ||
533 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
534 | ||
535 | gMC->Gspos("TLGA",ns+1,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
536 | ||
537 | nRotMat++; | |
538 | ||
539 | // reflection !! | |
540 | ||
541 | phi3 = 0.; | |
542 | theta3 = 180.; | |
543 | ||
544 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
545 | ||
546 | gMC->Gspos("TLGA",ns+1+nOuterSector,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
547 | ||
548 | nRotMat++; | |
549 | } | |
550 | ||
551 | else{ | |
552 | ||
553 | //--------------------------------------------------------------- | |
554 | // position selected sectors | |
555 | //--------------------------------------------------------------- | |
556 | ||
557 | for(Int_t sel=0;sel<12;sel++){ | |
558 | ||
559 | if(fSecUps[sel] == ns+2*nInnerSector){ | |
560 | ||
561 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
562 | gMC->Gspos("TLGA",ns+1,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
563 | nRotMat++; | |
564 | ||
565 | } | |
566 | else if(fSecUps[sel] == ns+2*nInnerSector+nOuterSector){ | |
567 | ||
568 | // reflection | |
569 | ||
570 | phi3 = 0.; | |
571 | theta3 = 180.; | |
572 | ||
573 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
574 | gMC-> | |
575 | Gspos("TLGA",ns+1+nOuterSector,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
576 | nRotMat++; | |
577 | ||
578 | } | |
579 | ||
580 | } | |
581 | ||
582 | } | |
583 | ||
584 | } | |
585 | ||
586 | Float_t z0 = z_side - 0.95; | |
587 | ||
588 | gMC->Gspos("TPEC",1,"TPSG",0.,0.,z0,0,"ONLY"); | |
589 | ||
590 | // ========================================================== | |
591 | // wheels | |
592 | // ========================================================== | |
593 | ||
594 | // | |
595 | // auxilary structures | |
596 | // | |
597 | ||
598 | ||
599 | gMC->Gsvolu("TPWI","TUBE",idtmed[24],dm,0); // "air" | |
600 | ||
601 | // ---------------------------------------------------------- | |
602 | // Large wheel -> positioned in the TPC | |
603 | // ---------------------------------------------------------- | |
604 | ||
605 | ||
606 | z0 = 263.5; // TPC length - 1/2 spoke wheel width | |
607 | ||
608 | dm[0] = 258.; | |
609 | dm[1] = 278.; | |
610 | dm[2] = 11.5; | |
611 | ||
612 | gMC->Gsvolu("TPWL", "TUBE", idtmed[0], dm, 3); | |
613 | ||
614 | dm[0] = dm[0]+2.; | |
615 | dm[1] = 278.; | |
616 | dm[2] = dm[2]-2.; | |
617 | ||
618 | gMC->Gsposp("TPWI",1,"TPWL",0.,0.,0.,0,"ONLY",dm,3); | |
619 | ||
620 | gMC->Gspos("TPWL", 1, "TPC ", 0, 0, z0, 0, "ONLY"); | |
621 | gMC->Gspos("TPWL", 2, "TPC ", 0, 0, -z0, 0, "ONLY"); | |
622 | ||
623 | // | |
624 | // Outer vessel + CO2 HV degrader | |
625 | // | |
626 | ||
627 | dm[0] = 260.; | |
628 | dm[1] = 278.; | |
629 | dm[2] = 252.; | |
630 | ||
631 | gMC->Gsvolu("TPCO","TUBE",idtmed[12],dm,3); | |
632 | ||
633 | dm[0] = 275.; | |
634 | dm[1] = 278.; | |
635 | ||
636 | gMC->Gsvolu("TPOV","TUBE",idtmed[10],dm,3); | |
637 | ||
638 | gMC->Gspos("TPOV",1,"TPCO",0.,0.,0.,0,"ONLY"); | |
639 | ||
640 | ||
641 | // G10 plugs | |
642 | ||
643 | dm[0] = 258.; | |
644 | dm[1] = 260.; | |
645 | dm[2] = 1.; | |
646 | ||
647 | gMC->Gsvolu("TPG1","TUBE",idtmed[8],dm,3); | |
648 | gMC->Gspos("TPG1",1,"TPCO",0.,0.,251.,0,"ONLY"); | |
649 | gMC->Gspos("TPG1",2,"TPCO",0.,0.,-251.,0,"ONLY"); | |
650 | ||
651 | gMC->Gspos("TPCO",1,"TPC ",0.,0.,0.,0,"ONLY"); | |
652 | ||
653 | ||
654 | //---------------------------------------------------------- | |
655 | // Small wheel -> positioned in "side gas | |
656 | //---------------------------------------------------------- | |
657 | ||
658 | dm[0] = 78.; | |
659 | dm[1] = 82.; | |
660 | dm[2] = 11.5; | |
661 | ||
662 | gMC->Gsvolu("TPWS", "TUBE", idtmed[0], dm, 3); | |
663 | ||
664 | dm[0] = 78.; | |
665 | dm[1] = dm[1]-2; | |
666 | dm[2] = dm[2]-2.; | |
667 | ||
668 | gMC->Gsvolu("TPW1", "TUBE", idtmed[2], dm, 3); | |
669 | ||
670 | gMC->Gspos("TPW1", 1, "TPWS", 0., 0., 0., 0, "ONLY"); | |
671 | ||
672 | z0 = 1.; // spoke wheel is shifted w.r.t. center of the "side gas" | |
673 | ||
674 | gMC->Gspos("TPWS", 1, "TPSG", 0, 0, z0, 0, "ONLY"); | |
675 | ||
676 | ||
677 | // to avoid overlaps | |
678 | ||
679 | dm[0] = 76.; | |
680 | dm[1] = 78.; | |
681 | dm[2] = 11.5; | |
682 | ||
683 | gMC->Gsvolu("TPS1","TUBE",idtmed[0],dm,3); | |
684 | ||
685 | dm[2] = 9.5; | |
686 | ||
687 | gMC->Gsvolu("TPS2","TUBE",idtmed[24],dm,3); | |
688 | ||
689 | gMC->Gspos("TPS2",1,"TPS1",0.,0.,0.,0,"ONLY"); | |
690 | ||
691 | z0= 263.5; | |
692 | ||
693 | gMC->Gspos("TPS1",1,"TPC ",0.,0.,z0,0,"ONLY"); | |
694 | gMC->Gspos("TPS1",2,"TPC ",0.,0.,-z0,0,"ONLY"); | |
695 | ||
696 | // G10 plug | |
697 | ||
698 | dm[0] = 76.; | |
7d7bb9e5 | 699 | dm[1] = 78.; |
700 | dm[2] = 1.; | |
1283eee5 | 701 | |
702 | gMC->Gsvolu("TPG2","TUBE",idtmed[8],dm,3); | |
703 | ||
704 | z0 = 251.; | |
705 | ||
706 | gMC->Gspos("TPG2",1,"TPC ",0.,0.,z0,0,"ONLY"); | |
707 | gMC->Gspos("TPG2",2,"TPC ",0.,0.,-z0,0,"ONLY"); | |
708 | ||
709 | ||
710 | //--------------------------------------------------------- | |
711 | // central wheel 6 (radial direction) x 4 (along z) cm2 | |
712 | //--------------------------------------------------------- | |
713 | ||
714 | dm[0] = 140.; | |
715 | dm[1] = 146.; | |
716 | dm[2] = 2.; | |
717 | ||
718 | gMC->Gsvolu("TPWC","TUBE",idtmed[0],dm,3); | |
719 | ||
720 | dm[0] = dm[0] + 2.; | |
721 | dm[1] = dm[1] - 2.; | |
722 | dm[2] = dm[2] - 1.; | |
723 | ||
724 | gMC->Gsposp("TPWI",2,"TPWC",0.,0.,0.,0,"ONLY",dm,3); | |
725 | ||
726 | z0 = z_side - 1.9 - 2.; | |
727 | ||
728 | gMC->Gspos("TPWC",1,"TPSG",0.,0.,z0,0,"ONLY"); | |
729 | ||
730 | // | |
731 | ||
732 | gMC->Gsvolu("TPSE","BOX ",idtmed[24],dm,0); // "empty" part of the spoke | |
733 | ||
734 | ||
735 | //--------------------------------------------------------- | |
736 | // inner spokes (nSectorInner) | |
737 | //--------------------------------------------------------- | |
738 | ||
739 | dm[0] = 0.5*(139.9-82.1); | |
740 | dm[1] = 3.; | |
741 | dm[2] = 2.; | |
742 | ||
743 | Float_t x1 = dm[0]+82.; | |
744 | ||
745 | gMC->Gsvolu("TPSI","BOX",idtmed[0],dm,3); | |
746 | ||
747 | dm[1] = dm[1]-1.; | |
748 | dm[2] = dm[2]-1.; | |
749 | ||
750 | gMC->Gsposp("TPSE",1,"TPSI",0.,0.,0.,0,"ONLY",dm,3); | |
751 | ||
752 | for(ns=0;ns<nInnerSector;ns++){ | |
753 | ||
754 | phi1 = 0.5*InnerOpenAngle + ns*InnerOpenAngle + InnerAngleShift; | |
755 | theta1=90.; | |
756 | phi1 *=kRaddeg; | |
757 | ||
758 | phi1 = (Float_t)TMath::Nint(phi1); | |
759 | if(phi1>360.) phi1 -= 360.; | |
760 | ||
761 | phi2 = phi1+90.; | |
762 | if(phi2>360.) phi2 -= 360.; | |
763 | theta2=90.; | |
764 | phi3=0.; | |
765 | theta3=0.; | |
766 | ||
767 | alpha = phi1 * kDegrad; | |
768 | x = x1 * TMath::Cos(alpha); | |
769 | y = x1 * TMath::Sin(alpha); | |
770 | ||
771 | AliMatrix(idrotm[nRotMat],theta1,phi1,theta2,phi2,theta3,phi3); | |
772 | ||
773 | gMC->Gspos("TPSI",ns+1,"TPSG",x,y,z0,idrotm[nRotMat],"ONLY"); | |
774 | ||
775 | nRotMat++; | |
776 | ||
777 | } | |
778 | ||
779 | //------------------------------------------------------------- | |
780 | // outer spokes (nSectorOuter) | |
781 | //------------------------------------------------------------- | |
782 | ||
783 | dm[0] = 0.5*(257.9-146.1); | |
784 | dm[1] = 3.; | |
785 | dm[2] = 2.; | |
786 | ||
787 | x1 = dm[0] + 146.; | |
788 | ||
789 | gMC->Gsvolu("TPSO","BOX ",idtmed[0],dm,3); | |
790 | ||
791 | dm[1] = dm[1] - 1.; | |
792 | dm[2] = dm[2] - 1.; | |
793 | ||
794 | gMC->Gsposp("TPSE",2,"TPSO",0.,0.,0.,0,"ONLY",dm,3); | |
795 | ||
796 | for(ns=0;ns<nOuterSector;ns++){ | |
797 | ||
798 | phi1 = 0.5*OuterOpenAngle + ns*OuterOpenAngle + OuterAngleShift; | |
799 | theta1=90.; | |
800 | phi1 *=kRaddeg; | |
801 | ||
802 | phi1 = (Float_t)TMath::Nint(phi1); | |
803 | if(phi1>360.) phi1 -= 360.; | |
804 | ||
805 | phi2 = phi1+90.; | |
806 | if(phi2>360.) phi2 -= 360.; | |
807 | theta2=90.; | |
808 | phi3=0.; | |
809 | theta3=0.; | |
810 | ||
811 | alpha = phi1 * kDegrad; | |
812 | x = x1 * TMath::Cos(alpha); | |
813 | y = x1 * TMath::Sin(alpha); | |
814 | ||
815 | AliMatrix(idrotm[nRotMat],theta1,phi1,theta2,phi2,theta3,phi3); | |
816 | ||
817 | gMC->Gspos("TPSO",ns+1,"TPSG",x,y,z0,idrotm[nRotMat],"ONLY"); | |
818 | ||
819 | nRotMat++; | |
820 | ||
821 | } | |
822 | ||
823 | ||
824 | ||
825 | // -------------------------------------------------------- | |
826 | // put the readout chambers into the TPC | |
827 | // -------------------------------------------------------- | |
828 | ||
829 | theta1 = 90.; | |
830 | phi1 = 0.; | |
831 | theta2 = 90.; | |
832 | phi2 = 270.; | |
833 | theta3 = 180.; | |
834 | phi3 = 0.; | |
835 | ||
836 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
837 | ||
838 | z0 = z_side + 250.; | |
839 | ||
840 | gMC->Gspos("TPSG", 1, "TPC ", 0, 0, z0, 0, "ONLY"); | |
841 | gMC->Gspos("TPSG", 2, "TPC ", 0, 0, -z0, idrotm[nRotMat], "ONLY"); | |
842 | ||
843 | gMC->Gspos("TPC ", 1, "ALIC", 0, 0, 0, 0, "ONLY"); | |
844 | ||
845 | //---------------------------------------------------- | |
846 | // Inner vessel and HV degrader | |
847 | //---------------------------------------------------- | |
848 | ||
849 | dm[0] = 0.; | |
850 | dm[1] = 360.; | |
851 | dm[2] = 4.; | |
852 | ||
853 | dm[3] = -250.; | |
854 | dm[4] = 74.4; | |
855 | dm[5] = 76.; | |
856 | ||
857 | dm[6] = -64.5; | |
858 | dm[7] = 50.; | |
859 | dm[8] = 76.; | |
860 | ||
861 | dm[9] = -64.5; | |
862 | dm[10] = 50.; | |
863 | dm[11] = 76.; | |
864 | ||
865 | dm[12] = 250.; | |
866 | dm[13] = 74.4; | |
867 | dm[14] = 76.; | |
868 | ||
869 | gMC->Gsvolu("TPVD", "PCON", idtmed[12], dm, 15); // CO2 | |
870 | ||
871 | // cone parts | |
872 | ||
873 | dm[0] = 0.; | |
874 | dm[1] = 360.; | |
875 | dm[2] = 2.; | |
876 | ||
877 | dm[3] = 64.5; | |
878 | dm[4] = 50.; | |
879 | dm[5] = 51.6; | |
880 | ||
881 | dm[6] = 250.; | |
882 | dm[7] = 74.4; | |
883 | dm[8] = 76.; | |
884 | ||
885 | ||
886 | gMC->Gsvolu("TIVC","PCON",idtmed[11],dm,9); // C-fibre | |
887 | ||
888 | gMC->Gspos("TIVC",1,"TPVD",0.,0.,0.,0,"ONLY"); | |
889 | gMC->Gspos("TIVC",2,"TPVD",0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
890 | ||
891 | // barrel part | |
892 | ||
893 | dm[0] = 50.; | |
894 | dm[1] = 50.5; | |
895 | dm[2] = 32.25; | |
896 | ||
897 | gMC->Gsvolu("TIVB","TUBE",idtmed[9],dm,3); | |
898 | ||
899 | gMC->Gspos("TIVB",1,"TPVD",0.,0.,0.,0,"ONLY"); | |
900 | ||
901 | gMC->Gspos("TPVD",1,"ALIC",0.,0.,0.,0,"ONLY"); | |
902 | ||
903 | ||
904 | // --------------------------------------------------- | |
905 | // volumes ordering | |
906 | // --------------------------------------------------- | |
907 | ||
908 | gMC->Gsord("TGAS", 6); | |
909 | gMC->Gsord("TPSG", 6); | |
910 | ||
911 | ||
912 | ||
913 | } // end of function | |
fe4da5cc | 914 | |
915 | //_____________________________________________________________________________ | |
8c555625 | 916 | void AliTPCv2::DrawDetector() |
fe4da5cc | 917 | { |
918 | // | |
919 | // Draw a shaded view of the Time Projection Chamber version 1 | |
920 | // | |
921 | ||
fe4da5cc | 922 | // Set everything unseen |
cfce8870 | 923 | gMC->Gsatt("*", "seen", -1); |
fe4da5cc | 924 | // |
925 | // Set ALIC mother transparent | |
cfce8870 | 926 | gMC->Gsatt("ALIC","SEEN",0); |
fe4da5cc | 927 | // |
928 | // Set the volumes visible | |
cfce8870 | 929 | gMC->Gsatt("TPC","SEEN",0); |
930 | gMC->Gsatt("TGAS","SEEN",0); | |
931 | gMC->Gsatt("TPSG","SEEN",0); | |
932 | gMC->Gsatt("TPHV","SEEN",1); | |
1283eee5 | 933 | gMC->Gsatt("TPMH","SEEN",1); |
934 | gMC->Gsatt("TPEC","SEEN",0); | |
cfce8870 | 935 | gMC->Gsatt("TRCS","SEEN",1); |
936 | gMC->Gsatt("TRCL","SEEN",1); | |
1283eee5 | 937 | gMC->Gsatt("TPWL","SEEN",1); |
938 | gMC->Gsatt("TPWI","SEEN",1); | |
939 | gMC->Gsatt("TPWS","SEEN",1); | |
cfce8870 | 940 | gMC->Gsatt("TPW1","SEEN",1); |
1283eee5 | 941 | gMC->Gsatt("TPS1","SEEN",1); |
942 | gMC->Gsatt("TPS2","SEEN",1); | |
943 | gMC->Gsatt("TPG1","SEEN",1); | |
944 | gMC->Gsatt("TPG2","SEEN",1); | |
945 | gMC->Gsatt("TPWC","SEEN",1); | |
946 | gMC->Gsatt("TPSI","SEEN",1); | |
947 | gMC->Gsatt("TPSO","SEEN",1); | |
948 | gMC->Gsatt("TPCO","SEEN",1); | |
949 | gMC->Gsatt("TPOV","SEEN",1); | |
cfce8870 | 950 | gMC->Gsatt("TPVD","SEEN",1); |
fe4da5cc | 951 | // |
cfce8870 | 952 | gMC->Gdopt("hide", "on"); |
953 | gMC->Gdopt("shad", "on"); | |
954 | gMC->Gsatt("*", "fill", 7); | |
955 | gMC->SetClipBox("."); | |
956 | gMC->SetClipBox("*", 0, 1000, -1000, 1000, -1000, 1000); | |
957 | gMC->DefaultRange(); | |
958 | gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025); | |
959 | gMC->Gdhead(1111, "Time Projection Chamber"); | |
960 | gMC->Gdman(18, 4, "MAN"); | |
961 | gMC->Gdopt("hide","off"); | |
fe4da5cc | 962 | } |
963 | ||
964 | //_____________________________________________________________________________ | |
965 | void AliTPCv2::CreateMaterials() | |
966 | { | |
967 | // | |
968 | // Define materials for version 2 of the Time Projection Chamber | |
969 | // | |
970 | ||
fe4da5cc | 971 | // |
972 | // Increase maximum number of steps | |
cfce8870 | 973 | gMC->SetMaxNStep(30000); |
fe4da5cc | 974 | // |
975 | AliTPC::CreateMaterials(); | |
976 | } | |
977 | ||
978 | //_____________________________________________________________________________ | |
979 | void AliTPCv2::Init() | |
980 | { | |
981 | // | |
982 | // Initialises version 2 of the TPC after that it has been built | |
983 | // | |
ad51aeb0 | 984 | Int_t *idtmed = fIdtmed->GetArray()-399; |
fe4da5cc | 985 | AliTPC::Init(); |
cfce8870 | 986 | fIdSens1=gMC->VolId("TLGA"); // L-sector |
987 | fIdSens2=gMC->VolId("TSGA"); // S-sector | |
988 | fIdSens3=gMC->VolId("TSST"); // strip - S-sector (not always used) | |
989 | fIdSens4=gMC->VolId("TLST"); // strip - S-sector (not always used) | |
fe4da5cc | 990 | |
cfce8870 | 991 | gMC->SetMaxNStep(30000); // max. number of steps increased |
fe4da5cc | 992 | |
cfce8870 | 993 | gMC->Gstpar(idtmed[403],"LOSS",5); |
fe4da5cc | 994 | |
995 | printf("*** TPC version 2 initialized ***\n"); | |
cfce8870 | 996 | printf("Maximum number of steps = %d\n",gMC->GetMaxNStep()); |
fe4da5cc | 997 | |
998 | // | |
999 | ||
1000 | } | |
1001 | ||
1002 | //_____________________________________________________________________________ | |
1003 | void AliTPCv2::StepManager() | |
1004 | { | |
1005 | // | |
1006 | // Called for every step in the Time Projection Chamber | |
1007 | // | |
1008 | ||
1009 | // | |
1010 | // parameters used for the energy loss calculations | |
1011 | // | |
62a73ee5 | 1012 | const Float_t prim = 14.35; // number of primary collisions per 1 cm |
1013 | const Float_t poti = 20.77e-9; // first ionization potential for Ne/CO2 | |
1014 | const Float_t w_ion = 35.97e-9; // energy for the ion-electron pair creation | |
8022212f | 1015 | |
1016 | // const Float_t prim = 17.65; | |
1017 | // const Float_t poti = 19.02e-9; | |
1018 | // const Float_t w_ion = 33.06e-9; | |
fe4da5cc | 1019 | |
1020 | ||
1021 | const Float_t big = 1.e10; | |
1022 | ||
1023 | Int_t id,copy; | |
1024 | Float_t hits[4]; | |
1025 | Int_t vol[2]; | |
1026 | TClonesArray &lhits = *fHits; | |
0a6d8768 | 1027 | TLorentzVector pos; |
1283eee5 | 1028 | |
1029 | AliTPCParam *fTPCParam = &(fDigParam->GetParam()); | |
fe4da5cc | 1030 | |
1031 | vol[1]=0; | |
1032 | ||
1033 | // | |
1034 | ||
cfce8870 | 1035 | gMC->SetMaxStep(big); |
fe4da5cc | 1036 | |
0a6d8768 | 1037 | if(!gMC->IsTrackAlive()) return; // particle has disappeared |
fe4da5cc | 1038 | |
cfce8870 | 1039 | Float_t charge = gMC->TrackCharge(); |
fe4da5cc | 1040 | |
1041 | if(TMath::Abs(charge)<=0.) return; // take only charged particles | |
1042 | ||
1043 | ||
0a6d8768 | 1044 | id=gMC->CurrentVolID(copy); |
fe4da5cc | 1045 | |
1046 | // Check the sensitive volume | |
1047 | ||
1048 | if(id == fIdSens1) | |
1049 | { | |
1283eee5 | 1050 | vol[0] = copy + fTPCParam->GetNInnerSector()-1; // L-sector number |
fe4da5cc | 1051 | } |
1052 | else if(id == fIdSens2) | |
1053 | { | |
1283eee5 | 1054 | vol[0] = copy-1; // S-sector number |
fe4da5cc | 1055 | } |
0a6d8768 | 1056 | else if(id == fIdSens3 && gMC->IsTrackEntering()) |
fe4da5cc | 1057 | { |
1283eee5 | 1058 | vol[1] = copy-1; // row number |
0a6d8768 | 1059 | id = gMC->CurrentVolOffID(1,copy); |
1283eee5 | 1060 | vol[0] = copy-1; // sector number (S-sector) |
fe4da5cc | 1061 | |
0a6d8768 | 1062 | gMC->TrackPosition(pos); |
1063 | hits[0]=pos[0]; | |
1064 | hits[1]=pos[1]; | |
1065 | hits[2]=pos[2]; | |
fe4da5cc | 1066 | hits[3]=0.; // this hit has no energy loss |
1067 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1068 | } | |
0a6d8768 | 1069 | else if(id == fIdSens4 && gMC->IsTrackEntering()) |
fe4da5cc | 1070 | { |
1283eee5 | 1071 | vol[1] = copy-1; // row number |
0a6d8768 | 1072 | id = gMC->CurrentVolOffID(1,copy); |
1283eee5 | 1073 | vol[0] = copy+fTPCParam->GetNInnerSector()-1; // sector number (L-sector) |
fe4da5cc | 1074 | |
0a6d8768 | 1075 | gMC->TrackPosition(pos); |
1076 | hits[0]=pos[0]; | |
1077 | hits[1]=pos[1]; | |
1078 | hits[2]=pos[2]; | |
fe4da5cc | 1079 | hits[3]=0.; // this hit has no energy loss |
1080 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1081 | } | |
1082 | else return; | |
1083 | ||
1084 | // | |
1085 | // charged particle is in the sensitive volume | |
1086 | // | |
1087 | ||
cfce8870 | 1088 | if(gMC->TrackStep() > 0) { |
fe4da5cc | 1089 | |
cfce8870 | 1090 | Int_t nel = (Int_t)(((gMC->Edep())-poti)/w_ion) + 1; |
fe4da5cc | 1091 | nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV |
1092 | ||
0a6d8768 | 1093 | gMC->TrackPosition(pos); |
1094 | hits[0]=pos[0]; | |
1095 | hits[1]=pos[1]; | |
1096 | hits[2]=pos[2]; | |
fe4da5cc | 1097 | hits[3]=(Float_t)nel; |
1098 | ||
1099 | // Add this hit | |
1100 | ||
1101 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1102 | ||
1103 | } | |
1104 | ||
1105 | // Stemax calculation for the next step | |
1106 | ||
1107 | Float_t pp; | |
0a6d8768 | 1108 | TLorentzVector mom; |
1109 | gMC->TrackMomentum(mom); | |
1110 | Float_t ptot=mom.Rho(); | |
1111 | Float_t beta_gamma = ptot/gMC->TrackMass(); | |
fe4da5cc | 1112 | |
8022212f | 1113 | if(gMC->IdFromPDG(gMC->TrackPid()) <= 3 && ptot > 0.002) |
fe4da5cc | 1114 | { |
1115 | pp = prim*1.58; // electrons above 20 MeV/c are on the plateau! | |
1116 | } | |
1117 | else | |
1118 | { | |
1119 | pp=prim*BetheBloch(beta_gamma); | |
1120 | if(TMath::Abs(charge) > 1.) pp *= (charge*charge); | |
1121 | } | |
1122 | ||
1123 | Float_t random[1]; | |
cfce8870 | 1124 | gMC->Rndm(random,1); // good, old GRNDM from Geant3 |
fe4da5cc | 1125 | |
1126 | Double_t rnd = (Double_t)random[0]; | |
1127 | ||
cfce8870 | 1128 | gMC->SetMaxStep(-TMath::Log(rnd)/pp); |
fe4da5cc | 1129 | |
1130 | } | |
1131 | ||
1132 | //_____________________________________________________________________________ | |
1133 | Float_t AliTPCv2::BetheBloch(Float_t bg) | |
1134 | { | |
1135 | // | |
1136 | // Bethe-Bloch energy loss formula | |
1137 | // | |
1138 | const Double_t p1=0.76176e-1; | |
1139 | const Double_t p2=10.632; | |
1140 | const Double_t p3=0.13279e-4; | |
1141 | const Double_t p4=1.8631; | |
1142 | const Double_t p5=1.9479; | |
1143 | ||
1144 | Double_t dbg = (Double_t) bg; | |
1145 | ||
1146 | Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg); | |
1147 | ||
1148 | Double_t aa = TMath::Power(beta,p4); | |
1149 | Double_t bb = TMath::Power(1./dbg,p5); | |
1150 | ||
1151 | bb=TMath::Log(p3+bb); | |
1152 | ||
1153 | return ((Float_t)((p2-aa-bb)*p1/aa)); | |
1154 | } |