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