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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 | $Log$ | |
18 | Revision 1.17 1999/10/08 06:27:23 fca | |
19 | Corrected bug in the HV degrader geometry, thanks to G.Tabary | |
20 | ||
21 | Revision 1.16 1999/10/04 13:39:54 fca | |
22 | Correct array index problem | |
23 | ||
24 | Revision 1.15 1999/09/29 09:24:34 fca | |
25 | Introduction of the Copyright and cvs Log | |
26 | ||
27 | */ | |
28 | ||
29 | /////////////////////////////////////////////////////////////////////////////// | |
30 | // // | |
31 | // Time Projection Chamber version 2 -- detailed TPC and slow simulation // | |
32 | // // | |
33 | //Begin_Html | |
34 | /* | |
35 | <img src="picts/AliTPCv2Class.gif"> | |
36 | */ | |
37 | //End_Html | |
38 | // // | |
39 | // // | |
40 | /////////////////////////////////////////////////////////////////////////////// | |
41 | #include <stdlib.h> | |
42 | ||
43 | #include <TMath.h> | |
44 | ||
45 | #include "AliTPCv2.h" | |
46 | #include "AliTPCD.h" | |
47 | #include "AliRun.h" | |
48 | #include "AliConst.h" | |
49 | #include "AliPDG.h" | |
50 | ||
51 | ClassImp(AliTPCv2) | |
52 | ||
53 | //_____________________________________________________________________________ | |
54 | AliTPCv2::AliTPCv2(const char *name, const char *title) : | |
55 | AliTPC(name, title) | |
56 | { | |
57 | // | |
58 | // Standard constructor for Time Projection Chamber version 2 | |
59 | // | |
60 | fIdSens1=0; | |
61 | fIdSens2=0; | |
62 | SetBufferSize(128000); | |
63 | } | |
64 | ||
65 | //_____________________________________________________________________________ | |
66 | void AliTPCv2::CreateGeometry() | |
67 | { | |
68 | // | |
69 | // Create the geometry of Time Projection Chamber version 2 | |
70 | // | |
71 | //Begin_Html | |
72 | /* | |
73 | <img src="picts/AliTPCv2.gif"> | |
74 | */ | |
75 | //End_Html | |
76 | //Begin_Html | |
77 | /* | |
78 | <img src="picts/AliTPCv2Tree.gif"> | |
79 | */ | |
80 | //End_Html | |
81 | ||
82 | AliTPCParam * fTPCParam = &(fDigParam->GetParam()); | |
83 | ||
84 | Int_t *idtmed = fIdtmed->GetArray(); | |
85 | ||
86 | Float_t dm[21]; | |
87 | Int_t idrotm[120]; | |
88 | ||
89 | Int_t nRotMat = 0; | |
90 | ||
91 | Int_t i,ifl1,ifl2; | |
92 | ||
93 | Int_t nInnerSector = fTPCParam->GetNInnerSector()/2; | |
94 | Int_t nOuterSector = fTPCParam->GetNOuterSector()/2; | |
95 | ||
96 | // --------------------------------------------------- | |
97 | // sector specification check | |
98 | // --------------------------------------------------- | |
99 | if (fSecAL >= 0) { | |
100 | ifl1 = 0; | |
101 | ||
102 | for (i = 0; i < 6; ++i) { | |
103 | if (fSecLows[i] >= 0 && fSecLows[i] < 2*nInnerSector) { | |
104 | ifl1 = 1; | |
105 | printf("*** SECTOR %d selected\n",fSecLows[i]); | |
106 | } | |
107 | } | |
108 | ||
109 | } else { | |
110 | printf("*** ALL LOWER SECTORS SELECTED ***\n"); | |
111 | ifl1 = 1; | |
112 | } | |
113 | ||
114 | if (fSecAU >= 0) { | |
115 | ifl2 = 0; | |
116 | ||
117 | for (i = 0; i < 12; ++i) { | |
118 | if (fSecUps[i] > 2*nInnerSector-1 && | |
119 | fSecUps[i] < 2*(nInnerSector+nOuterSector)) { | |
120 | ifl2 = 1; | |
121 | printf("*** SECTOR %d selected\n",fSecUps[i]); | |
122 | } | |
123 | } | |
124 | ||
125 | } else { | |
126 | printf("*** ALL UPPER SECTORS SELECTED ***\n"); | |
127 | ifl1 = 1; | |
128 | } | |
129 | ||
130 | if (ifl1 == 0 && ifl2 == 0) { | |
131 | printf("*** ERROR: AT LEAST ONE SECTOR MUST BE SPECIFIED ***\n"); | |
132 | printf("!!! PROGRAM STOPPED !!!\n"); | |
133 | exit(1); | |
134 | } | |
135 | ||
136 | if ((fSecAL < 0 || fSecAU < 0) && fSens >= 0) { | |
137 | printf("** ERROR: STRIPS CANNOT BE SPECIFIED FOR ALL SECTORS **\n"); | |
138 | printf("!!! PROGRAM STOPPED !!!\n"); | |
139 | exit(1); | |
140 | } | |
141 | ||
142 | // ---------------------------------------------------- | |
143 | // FIELD CAGE WITH ENDCAPS - G10 | |
144 | // THIS IS ALSO A TPC MOTHER VOLUME | |
145 | // ---------------------------------------------------- | |
146 | ||
147 | dm[0] = 76.; | |
148 | dm[1] = 278.; | |
149 | dm[2] = 275.; | |
150 | ||
151 | gMC->Gsvolu("TPC ", "TUBE", idtmed[8], dm, 3); | |
152 | ||
153 | //----------------------------------------------------- | |
154 | // Endcap cover c-fibre 0.86% X0 | |
155 | //----------------------------------------------------- | |
156 | ||
157 | dm[0] = 78.; | |
158 | dm[1] = 258.; | |
159 | dm[2] = 0.95; | |
160 | ||
161 | gMC->Gsvolu("TPEC","TUBE",idtmed[10],dm,3); | |
162 | ||
163 | //----------------------------------------------------- | |
164 | // Drift gas , leave 2 cm at the outer radius | |
165 | // and inner raddius | |
166 | //----------------------------------------------------- | |
167 | ||
168 | dm[0] = 78.; | |
169 | dm[1] = 258.; | |
170 | dm[2] = 250.; | |
171 | ||
172 | gMC->Gsvolu("TGAS", "TUBE", idtmed[3], dm, 3); | |
173 | ||
174 | //------------------------------------------------------ | |
175 | // membrane holder - carbon fiber | |
176 | //------------------------------------------------------ | |
177 | ||
178 | ||
179 | gMC->Gsvolu("TPMH","TUBE",idtmed[6],dm,0); | |
180 | ||
181 | dm[0] = 252.; | |
182 | dm[1] = 258.; | |
183 | dm[2] = 0.2; | |
184 | ||
185 | gMC->Gsposp("TPMH",1,"TGAS",0.,0.,0.,0,"ONLY",dm,3); | |
186 | ||
187 | dm[0] = 78.; | |
188 | dm[1] = 82.; | |
189 | dm[2] = 0.1; | |
190 | ||
191 | gMC->Gsposp("TPMH",2,"TGAS",0.,0.,0.,0,"ONLY",dm,3); | |
192 | ||
193 | //---------------------------------------------------------- | |
194 | // HV membrane - 25 microns of mylar | |
195 | //---------------------------------------------------------- | |
196 | ||
197 | dm[0] = 82.; | |
198 | dm[1] = 252.; | |
199 | dm[2] = 0.00125; | |
200 | ||
201 | gMC->Gsvolu("TPHV","TUBE",idtmed[5],dm,3); | |
202 | ||
203 | gMC->Gspos("TPHV",1,"TGAS",0.,0.,0.,0,"ONLY"); | |
204 | ||
205 | gMC->Gspos("TGAS",1,"TPC ",0.,0.,0.,0,"ONLY"); | |
206 | ||
207 | //---------------------------------------------------------- | |
208 | // "side" gas volume, the same as the drift gas | |
209 | // the readout chambers are placed there. | |
210 | //---------------------------------------------------------- | |
211 | ||
212 | dm[0] = 78.; | |
213 | dm[1] = 258.; | |
214 | dm[2] = 0.5*(275. - 250.); | |
215 | ||
216 | gMC->Gsvolu("TPSG", "TUBE", idtmed[2], dm, 3); | |
217 | ||
218 | Float_t z_side = dm[2]; // 1/2 of the side gas thickness | |
219 | ||
220 | //----------------------------------------------------------- | |
221 | // Readout chambers , 25% of X0, I use Al as the material | |
222 | //----------------------------------------------------------- | |
223 | ||
224 | Float_t InnerOpenAngle = fTPCParam->GetInnerAngle(); | |
225 | Float_t OuterOpenAngle = fTPCParam->GetOuterAngle(); | |
226 | ||
227 | Float_t InnerAngleShift = fTPCParam->GetInnerAngleShift(); | |
228 | Float_t OuterAngleShift = fTPCParam->GetOuterAngleShift(); | |
229 | ||
230 | Float_t InSecLowEdge = fTPCParam->GetInSecLowEdge(); | |
231 | Float_t InSecUpEdge = fTPCParam->GetInSecUpEdge(); | |
232 | ||
233 | Float_t OuSecLowEdge = fTPCParam->GetOuSecLowEdge(); | |
234 | Float_t OuSecUpEdge = fTPCParam->GetOuSecUpEdge(); | |
235 | ||
236 | ||
237 | Float_t SecThick = 2.225; // Al | |
238 | ||
239 | Float_t edge = fTPCParam->GetEdge(); | |
240 | ||
241 | // S (Inner) sectors | |
242 | ||
243 | dm[0] = InSecLowEdge*TMath::Tan(0.5*InnerOpenAngle)-edge; | |
244 | dm[1] = InSecUpEdge*TMath::Tan(0.5*InnerOpenAngle)-edge; | |
245 | dm[2] = 0.5*SecThick; | |
246 | dm[3] = 0.5*(InSecUpEdge-InSecLowEdge); | |
247 | ||
248 | Float_t xCenterS = InSecLowEdge+dm[3]; | |
249 | ||
250 | gMC->Gsvolu("TRCS", "TRD1", idtmed[0], dm, 4); | |
251 | ||
252 | // L (Outer) sectors | |
253 | ||
254 | dm[0] = OuSecLowEdge*TMath::Tan(0.5*OuterOpenAngle)-edge; | |
255 | dm[1] = OuSecUpEdge*TMath::Tan(0.5*OuterOpenAngle)-edge; | |
256 | dm[2] = 0.5*SecThick; | |
257 | dm[3] = 0.5*(OuSecUpEdge-OuSecLowEdge); | |
258 | ||
259 | Float_t xCenterL = OuSecLowEdge+dm[3]; | |
260 | ||
261 | gMC->Gsvolu("TRCL", "TRD1", idtmed[0], dm, 4); | |
262 | ||
263 | Float_t z1 = -z_side + SecThick*0.5; | |
264 | ||
265 | //------------------------------------------------------------------ | |
266 | // S sectors - "gas sectors" (TRD1) | |
267 | //------------------------------------------------------------------ | |
268 | ||
269 | dm[0] = InSecLowEdge*TMath::Tan(0.5*InnerOpenAngle)-0.01; | |
270 | dm[1] = InSecUpEdge*TMath::Tan(0.5*InnerOpenAngle)-0.01; | |
271 | dm[2] = 0.5*(250. - 0.001); | |
272 | dm[3] = 0.5*(InSecUpEdge-InSecLowEdge); | |
273 | ||
274 | gMC->Gsvolu("TSGA", "TRD1", idtmed[4], dm, 4); // sensitive | |
275 | ||
276 | // ------------------------------------------------------------- | |
277 | // Only for the debugging purpose and resolution calculation | |
278 | // Sensitive strips at the pad-row center | |
279 | // ------------------------------------------------------------- | |
280 | ||
281 | Int_t ns; | |
282 | ||
283 | if(fSens>=0){ | |
284 | ||
285 | Float_t r1,r2,zz; | |
286 | ||
287 | Float_t StripThick = 0.01; // 100 microns | |
288 | Float_t dead = fTPCParam->GetDeadZone(); | |
289 | ||
290 | gMC->Gsvolu("TSST", "TRD1", idtmed[4], dm, 0); | |
291 | ||
292 | dm[2] = 0.5*(250. - 0.002); | |
293 | dm[3] = 0.5 * StripThick; | |
294 | ||
295 | ||
296 | for (ns = 0; ns < fTPCParam->GetNRowLow(); ns++) { | |
297 | ||
298 | r1 = fTPCParam->GetPadRowRadiiLow(ns); | |
299 | r2 = r1 + StripThick; | |
300 | dm[0] = r1 * TMath::Tan(0.5*InnerOpenAngle) - dead; | |
301 | dm[1] = r2 * TMath::Tan(0.5*InnerOpenAngle) - dead; | |
302 | ||
303 | zz = -InSecLowEdge -0.5*(InSecUpEdge-InSecLowEdge); | |
304 | zz += r1; | |
305 | zz += dm[3]; | |
306 | ||
307 | gMC->Gsposp("TSST", ns+1, "TSGA", 0., 0., zz, 0, "ONLY", dm, 4); | |
308 | ||
309 | ||
310 | } | |
311 | ||
312 | gMC->Gsord("TSGA", 3); | |
313 | ||
314 | } // if strips selected | |
315 | ||
316 | ||
317 | //----------------------------------------------------------------- | |
318 | // L sectors - "gas sectors" (PGON to avoid overlaps) | |
319 | //----------------------------------------------------------------- | |
320 | ||
321 | dm[0] = 360.*kDegrad - 0.5*OuterOpenAngle; | |
322 | dm[0] *= kRaddeg; | |
323 | dm[0] = (Float_t)TMath::Nint(dm[0]); | |
324 | ||
325 | dm[1] = OuterOpenAngle*kRaddeg; | |
326 | dm[1] = (Float_t)TMath::Nint(dm[1]); | |
327 | ||
328 | dm[2] = 1.; | |
329 | dm[3] = 4.; | |
330 | ||
331 | dm[4] = 0.002; | |
332 | dm[5] = OuSecLowEdge; | |
333 | dm[6] = 252.*TMath::Cos(0.5*OuterOpenAngle)-0.002; | |
334 | ||
335 | dm[7] = dm[4]+0.2; | |
336 | dm[8] = dm[5]; | |
337 | dm[9] = dm[6]; | |
338 | ||
339 | dm[10] = dm[7]; | |
340 | dm[11] = OuSecLowEdge; | |
341 | dm[12] = OuSecUpEdge; | |
342 | ||
343 | dm[13] = 250.; | |
344 | dm[14] = dm[11]; | |
345 | dm[15] = dm[12]; | |
346 | ||
347 | gMC->Gsvolu("TLGA","PGON",idtmed[4],dm,16); | |
348 | ||
349 | if (fSens >= 0) { | |
350 | ||
351 | Float_t rmax = dm[6]; | |
352 | Float_t r1,r2; | |
353 | Float_t dead = fTPCParam->GetDeadZone(); | |
354 | ||
355 | Float_t StripThick = 0.01; // 100 microns | |
356 | ||
357 | gMC->Gsvolu("TLST", "PGON", idtmed[4], dm, 0); | |
358 | ||
359 | dm[0] = 360.*kDegrad - 0.5*OuterOpenAngle; | |
360 | dm[0] *= kRaddeg; | |
361 | dm[0] = (Float_t)TMath::Nint(dm[0]); | |
362 | ||
363 | dm[1] = OuterOpenAngle*kRaddeg; | |
364 | dm[1] = (Float_t)TMath::Nint(dm[1]); | |
365 | ||
366 | dm[2] = 1.; | |
367 | dm[3] = 2.; | |
368 | ||
369 | dm[7] = 250.; | |
370 | ||
371 | Float_t xx = dead/TMath::Tan(0.5*OuterOpenAngle); | |
372 | ||
373 | for(ns=0;ns<fTPCParam->GetNRowUp();ns++){ | |
374 | ||
375 | r1 = fTPCParam->GetPadRowRadiiUp(ns)-xx; | |
376 | r2 = r1 + StripThick; | |
377 | ||
378 | dm[5] = r1; | |
379 | dm[6] = r2; | |
380 | ||
381 | dm[8] = r1; | |
382 | dm[9] = r2; | |
383 | ||
384 | if(r2+xx < rmax){ | |
385 | dm[4] = 0.002; | |
386 | } | |
387 | else{ | |
388 | dm[4] = 0.202; | |
389 | } | |
390 | ||
391 | gMC->Gsposp("TLST",ns+1,"TLGA",xx,0.,0.,0,"ONLY",dm,10); | |
392 | ||
393 | } | |
394 | ||
395 | gMC->Gsord("TLGA", 4); | |
396 | ||
397 | } // if strips selected | |
398 | ||
399 | //------------------------------------------------------------------ | |
400 | // Positioning of the S-sector readout chambers | |
401 | //------------------------------------------------------------------ | |
402 | ||
403 | Float_t zs = 0.5*(250.+0.002); | |
404 | ||
405 | Float_t theta1,theta2,theta3; | |
406 | Float_t phi1,phi2,phi3; | |
407 | Float_t alpha; | |
408 | Float_t x,y; | |
409 | ||
410 | for(ns=0;ns<nInnerSector;ns++){ | |
411 | ||
412 | phi1 = ns * InnerOpenAngle + 270.*kDegrad + InnerAngleShift; | |
413 | phi1 *= kRaddeg; // in degrees | |
414 | ||
415 | phi1 = (Float_t)TMath::Nint(phi1); | |
416 | ||
417 | if (phi1 > 360.) phi1 -= 360.; | |
418 | ||
419 | theta1 = 90.; | |
420 | phi2 = 90.; | |
421 | theta2 = 180.; | |
422 | phi3 = ns * InnerOpenAngle + InnerAngleShift; | |
423 | phi3 *= kRaddeg; // in degrees | |
424 | ||
425 | phi3 = (Float_t)TMath::Nint(phi3); | |
426 | ||
427 | if(phi3 > 360.) phi3 -= 360.; | |
428 | ||
429 | theta3 = 90.; | |
430 | ||
431 | alpha = phi3*kDegrad; | |
432 | ||
433 | x = xCenterS * TMath::Cos(alpha); | |
434 | y = xCenterS * TMath::Sin(alpha); | |
435 | ||
436 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
437 | ||
438 | gMC->Gspos("TRCS", ns+1, "TPSG", x, y, z1, idrotm[nRotMat], "ONLY"); | |
439 | ||
440 | if(fSecAL < 0){ | |
441 | ||
442 | //--------------------------------------------------------------- | |
443 | // position all sectors | |
444 | //--------------------------------------------------------------- | |
445 | ||
446 | gMC->Gspos("TSGA",ns+1,"TGAS",x,y,zs,idrotm[nRotMat], "ONLY"); | |
447 | gMC->Gspos("TSGA",ns+1+nInnerSector,"TGAS",x,y,-zs,idrotm[nRotMat], "ONLY"); | |
448 | } | |
449 | ||
450 | else{ | |
451 | ||
452 | //--------------------------------------------------------------- | |
453 | // position selected sectors | |
454 | //--------------------------------------------------------------- | |
455 | ||
456 | for(Int_t sel=0;sel<6;sel++){ | |
457 | ||
458 | if(fSecLows[sel] == ns){ | |
459 | gMC->Gspos("TSGA", ns+1, "TGAS", x, y, zs, idrotm[nRotMat], "ONLY"); | |
460 | } | |
461 | else if(fSecLows[sel] == ns+nInnerSector){ | |
462 | gMC-> | |
463 | Gspos("TSGA",ns+1+nInnerSector,"TGAS", x, y,-zs,idrotm[nRotMat],"ONLY"); | |
464 | } | |
465 | } | |
466 | } | |
467 | ||
468 | nRotMat++; | |
469 | ||
470 | } | |
471 | ||
472 | //------------------------------------------------------------------- | |
473 | // Positioning of the L-sectors readout chambers | |
474 | //------------------------------------------------------------------- | |
475 | ||
476 | for(ns=0;ns<nOuterSector;ns++){ | |
477 | phi1 = ns * OuterOpenAngle + 270.*kDegrad + OuterAngleShift; | |
478 | phi1 *= kRaddeg; // in degrees | |
479 | ||
480 | phi1 = (Float_t)TMath::Nint(phi1); | |
481 | ||
482 | ||
483 | if (phi1 > 360.) phi1 -= 360.; | |
484 | ||
485 | theta1 = 90.; | |
486 | phi2 = 90.; | |
487 | theta2 = 180.; | |
488 | phi3 = ns * OuterOpenAngle+OuterAngleShift; | |
489 | phi3 *= kRaddeg; // in degrees | |
490 | ||
491 | phi3 = (Float_t)TMath::Nint(phi3); | |
492 | ||
493 | ||
494 | if(phi3 > 360.) phi3 -= 360.; | |
495 | ||
496 | theta3 = 90.; | |
497 | ||
498 | alpha = phi3*kDegrad; | |
499 | ||
500 | x = xCenterL * TMath::Cos(alpha); | |
501 | y = xCenterL * TMath::Sin(alpha); | |
502 | ||
503 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
504 | ||
505 | ||
506 | gMC->Gspos("TRCL", ns+1, "TPSG", x, y, z1, idrotm[nRotMat], "ONLY"); | |
507 | ||
508 | nRotMat++; | |
509 | ||
510 | } | |
511 | ||
512 | //------------------------------------------------------------------- | |
513 | // Positioning of the L-sectors (gas sectors) | |
514 | //------------------------------------------------------------------- | |
515 | ||
516 | for(ns=0;ns<nOuterSector;ns++){ | |
517 | ||
518 | phi1 = ns*OuterOpenAngle + OuterAngleShift; | |
519 | phi1 *= kRaddeg; | |
520 | ||
521 | phi1 = (Float_t)TMath::Nint(phi1); | |
522 | if(phi1>360.) phi1 -= 360.; | |
523 | ||
524 | theta1 = 90.; | |
525 | ||
526 | phi2 = 90. + phi1; | |
527 | if(phi2>360.) phi2 -= 360.; | |
528 | ||
529 | theta2 = 90.; | |
530 | ||
531 | phi3 = 0.; | |
532 | theta3 = 0.; | |
533 | ||
534 | if(fSecAU < 0) { | |
535 | ||
536 | //-------------------------------------------------------------- | |
537 | // position all sectors | |
538 | //-------------------------------------------------------------- | |
539 | ||
540 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
541 | ||
542 | gMC->Gspos("TLGA",ns+1,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
543 | ||
544 | nRotMat++; | |
545 | ||
546 | // reflection !! | |
547 | ||
548 | phi3 = 0.; | |
549 | theta3 = 180.; | |
550 | ||
551 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
552 | ||
553 | gMC->Gspos("TLGA",ns+1+nOuterSector,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
554 | ||
555 | nRotMat++; | |
556 | } | |
557 | ||
558 | else{ | |
559 | ||
560 | //--------------------------------------------------------------- | |
561 | // position selected sectors | |
562 | //--------------------------------------------------------------- | |
563 | ||
564 | for(Int_t sel=0;sel<12;sel++){ | |
565 | ||
566 | if(fSecUps[sel] == ns+2*nInnerSector){ | |
567 | ||
568 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
569 | gMC->Gspos("TLGA",ns+1,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
570 | nRotMat++; | |
571 | ||
572 | } | |
573 | else if(fSecUps[sel] == ns+2*nInnerSector+nOuterSector){ | |
574 | ||
575 | // reflection | |
576 | ||
577 | phi3 = 0.; | |
578 | theta3 = 180.; | |
579 | ||
580 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
581 | gMC-> | |
582 | Gspos("TLGA",ns+1+nOuterSector,"TGAS" ,0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
583 | nRotMat++; | |
584 | ||
585 | } | |
586 | ||
587 | } | |
588 | ||
589 | } | |
590 | ||
591 | } | |
592 | ||
593 | Float_t z0 = z_side - 0.95; | |
594 | ||
595 | gMC->Gspos("TPEC",1,"TPSG",0.,0.,z0,0,"ONLY"); | |
596 | ||
597 | // ========================================================== | |
598 | // wheels | |
599 | // ========================================================== | |
600 | ||
601 | // | |
602 | // auxilary structures | |
603 | // | |
604 | ||
605 | ||
606 | gMC->Gsvolu("TPWI","TUBE",idtmed[24],dm,0); // "air" | |
607 | ||
608 | // ---------------------------------------------------------- | |
609 | // Large wheel -> positioned in the TPC | |
610 | // ---------------------------------------------------------- | |
611 | ||
612 | ||
613 | z0 = 263.5; // TPC length - 1/2 spoke wheel width | |
614 | ||
615 | dm[0] = 258.; | |
616 | dm[1] = 278.; | |
617 | dm[2] = 11.5; | |
618 | ||
619 | gMC->Gsvolu("TPWL", "TUBE", idtmed[0], dm, 3); | |
620 | ||
621 | dm[0] = dm[0]+2.; | |
622 | dm[1] = 278.; | |
623 | dm[2] = dm[2]-2.; | |
624 | ||
625 | gMC->Gsposp("TPWI",1,"TPWL",0.,0.,0.,0,"ONLY",dm,3); | |
626 | ||
627 | gMC->Gspos("TPWL", 1, "TPC ", 0, 0, z0, 0, "ONLY"); | |
628 | gMC->Gspos("TPWL", 2, "TPC ", 0, 0, -z0, 0, "ONLY"); | |
629 | ||
630 | // | |
631 | // Outer vessel + CO2 HV degrader | |
632 | // | |
633 | ||
634 | dm[0] = 260.; | |
635 | dm[1] = 278.; | |
636 | dm[2] = 252.; | |
637 | ||
638 | gMC->Gsvolu("TPCO","TUBE",idtmed[12],dm,3); | |
639 | ||
640 | dm[0] = 275.; | |
641 | dm[1] = 278.; | |
642 | ||
643 | gMC->Gsvolu("TPOV","TUBE",idtmed[10],dm,3); | |
644 | ||
645 | gMC->Gspos("TPOV",1,"TPCO",0.,0.,0.,0,"ONLY"); | |
646 | ||
647 | ||
648 | // G10 plugs | |
649 | ||
650 | dm[0] = 258.; | |
651 | dm[1] = 260.; | |
652 | dm[2] = 1.; | |
653 | ||
654 | gMC->Gsvolu("TPG1","TUBE",idtmed[8],dm,3); | |
655 | gMC->Gspos("TPG1",1,"TPCO",0.,0.,251.,0,"ONLY"); | |
656 | gMC->Gspos("TPG1",2,"TPCO",0.,0.,-251.,0,"ONLY"); | |
657 | ||
658 | gMC->Gspos("TPCO",1,"TPC ",0.,0.,0.,0,"ONLY"); | |
659 | ||
660 | ||
661 | //---------------------------------------------------------- | |
662 | // Small wheel -> positioned in "side gas | |
663 | //---------------------------------------------------------- | |
664 | ||
665 | dm[0] = 78.; | |
666 | dm[1] = 82.; | |
667 | dm[2] = 11.5; | |
668 | ||
669 | gMC->Gsvolu("TPWS", "TUBE", idtmed[0], dm, 3); | |
670 | ||
671 | dm[0] = 78.; | |
672 | dm[1] = dm[1]-2; | |
673 | dm[2] = dm[2]-2.; | |
674 | ||
675 | gMC->Gsvolu("TPW1", "TUBE", idtmed[2], dm, 3); | |
676 | ||
677 | gMC->Gspos("TPW1", 1, "TPWS", 0., 0., 0., 0, "ONLY"); | |
678 | ||
679 | z0 = 1.; // spoke wheel is shifted w.r.t. center of the "side gas" | |
680 | ||
681 | gMC->Gspos("TPWS", 1, "TPSG", 0, 0, z0, 0, "ONLY"); | |
682 | ||
683 | ||
684 | // to avoid overlaps | |
685 | ||
686 | dm[0] = 76.; | |
687 | dm[1] = 78.; | |
688 | dm[2] = 11.5; | |
689 | ||
690 | gMC->Gsvolu("TPS1","TUBE",idtmed[0],dm,3); | |
691 | ||
692 | dm[2] = 9.5; | |
693 | ||
694 | gMC->Gsvolu("TPS2","TUBE",idtmed[24],dm,3); | |
695 | ||
696 | gMC->Gspos("TPS2",1,"TPS1",0.,0.,0.,0,"ONLY"); | |
697 | ||
698 | z0= 263.5; | |
699 | ||
700 | gMC->Gspos("TPS1",1,"TPC ",0.,0.,z0,0,"ONLY"); | |
701 | gMC->Gspos("TPS1",2,"TPC ",0.,0.,-z0,0,"ONLY"); | |
702 | ||
703 | // G10 plug | |
704 | ||
705 | dm[0] = 76.; | |
706 | dm[1] = 78.; | |
707 | dm[2] = 1.; | |
708 | ||
709 | gMC->Gsvolu("TPG2","TUBE",idtmed[8],dm,3); | |
710 | ||
711 | z0 = 251.; | |
712 | ||
713 | gMC->Gspos("TPG2",1,"TPC ",0.,0.,z0,0,"ONLY"); | |
714 | gMC->Gspos("TPG2",2,"TPC ",0.,0.,-z0,0,"ONLY"); | |
715 | ||
716 | ||
717 | //--------------------------------------------------------- | |
718 | // central wheel 6 (radial direction) x 4 (along z) cm2 | |
719 | //--------------------------------------------------------- | |
720 | ||
721 | dm[0] = 140.; | |
722 | dm[1] = 146.; | |
723 | dm[2] = 2.; | |
724 | ||
725 | gMC->Gsvolu("TPWC","TUBE",idtmed[0],dm,3); | |
726 | ||
727 | dm[0] = dm[0] + 2.; | |
728 | dm[1] = dm[1] - 2.; | |
729 | dm[2] = dm[2] - 1.; | |
730 | ||
731 | gMC->Gsposp("TPWI",2,"TPWC",0.,0.,0.,0,"ONLY",dm,3); | |
732 | ||
733 | z0 = z_side - 1.9 - 2.; | |
734 | ||
735 | gMC->Gspos("TPWC",1,"TPSG",0.,0.,z0,0,"ONLY"); | |
736 | ||
737 | // | |
738 | ||
739 | gMC->Gsvolu("TPSE","BOX ",idtmed[24],dm,0); // "empty" part of the spoke | |
740 | ||
741 | ||
742 | //--------------------------------------------------------- | |
743 | // inner spokes (nSectorInner) | |
744 | //--------------------------------------------------------- | |
745 | ||
746 | dm[0] = 0.5*(139.9-82.1); | |
747 | dm[1] = 3.; | |
748 | dm[2] = 2.; | |
749 | ||
750 | Float_t x1 = dm[0]+82.; | |
751 | ||
752 | gMC->Gsvolu("TPSI","BOX",idtmed[0],dm,3); | |
753 | ||
754 | dm[1] = dm[1]-1.; | |
755 | dm[2] = dm[2]-1.; | |
756 | ||
757 | gMC->Gsposp("TPSE",1,"TPSI",0.,0.,0.,0,"ONLY",dm,3); | |
758 | ||
759 | for(ns=0;ns<nInnerSector;ns++){ | |
760 | ||
761 | phi1 = 0.5*InnerOpenAngle + ns*InnerOpenAngle + InnerAngleShift; | |
762 | theta1=90.; | |
763 | phi1 *=kRaddeg; | |
764 | ||
765 | phi1 = (Float_t)TMath::Nint(phi1); | |
766 | if(phi1>360.) phi1 -= 360.; | |
767 | ||
768 | phi2 = phi1+90.; | |
769 | if(phi2>360.) phi2 -= 360.; | |
770 | theta2=90.; | |
771 | phi3=0.; | |
772 | theta3=0.; | |
773 | ||
774 | alpha = phi1 * kDegrad; | |
775 | x = x1 * TMath::Cos(alpha); | |
776 | y = x1 * TMath::Sin(alpha); | |
777 | ||
778 | AliMatrix(idrotm[nRotMat],theta1,phi1,theta2,phi2,theta3,phi3); | |
779 | ||
780 | gMC->Gspos("TPSI",ns+1,"TPSG",x,y,z0,idrotm[nRotMat],"ONLY"); | |
781 | ||
782 | nRotMat++; | |
783 | ||
784 | } | |
785 | ||
786 | //------------------------------------------------------------- | |
787 | // outer spokes (nSectorOuter) | |
788 | //------------------------------------------------------------- | |
789 | ||
790 | dm[0] = 0.5*(257.9-146.1); | |
791 | dm[1] = 3.; | |
792 | dm[2] = 2.; | |
793 | ||
794 | x1 = dm[0] + 146.; | |
795 | ||
796 | gMC->Gsvolu("TPSO","BOX ",idtmed[0],dm,3); | |
797 | ||
798 | dm[1] = dm[1] - 1.; | |
799 | dm[2] = dm[2] - 1.; | |
800 | ||
801 | gMC->Gsposp("TPSE",2,"TPSO",0.,0.,0.,0,"ONLY",dm,3); | |
802 | ||
803 | for(ns=0;ns<nOuterSector;ns++){ | |
804 | ||
805 | phi1 = 0.5*OuterOpenAngle + ns*OuterOpenAngle + OuterAngleShift; | |
806 | theta1=90.; | |
807 | phi1 *=kRaddeg; | |
808 | ||
809 | phi1 = (Float_t)TMath::Nint(phi1); | |
810 | if(phi1>360.) phi1 -= 360.; | |
811 | ||
812 | phi2 = phi1+90.; | |
813 | if(phi2>360.) phi2 -= 360.; | |
814 | theta2=90.; | |
815 | phi3=0.; | |
816 | theta3=0.; | |
817 | ||
818 | alpha = phi1 * kDegrad; | |
819 | x = x1 * TMath::Cos(alpha); | |
820 | y = x1 * TMath::Sin(alpha); | |
821 | ||
822 | AliMatrix(idrotm[nRotMat],theta1,phi1,theta2,phi2,theta3,phi3); | |
823 | ||
824 | gMC->Gspos("TPSO",ns+1,"TPSG",x,y,z0,idrotm[nRotMat],"ONLY"); | |
825 | ||
826 | nRotMat++; | |
827 | ||
828 | } | |
829 | ||
830 | ||
831 | ||
832 | // -------------------------------------------------------- | |
833 | // put the readout chambers into the TPC | |
834 | // -------------------------------------------------------- | |
835 | ||
836 | theta1 = 90.; | |
837 | phi1 = 0.; | |
838 | theta2 = 90.; | |
839 | phi2 = 270.; | |
840 | theta3 = 180.; | |
841 | phi3 = 0.; | |
842 | ||
843 | AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3); | |
844 | ||
845 | z0 = z_side + 250.; | |
846 | ||
847 | gMC->Gspos("TPSG", 1, "TPC ", 0, 0, z0, 0, "ONLY"); | |
848 | gMC->Gspos("TPSG", 2, "TPC ", 0, 0, -z0, idrotm[nRotMat], "ONLY"); | |
849 | ||
850 | gMC->Gspos("TPC ", 1, "ALIC", 0, 0, 0, 0, "ONLY"); | |
851 | ||
852 | //---------------------------------------------------- | |
853 | // Inner vessel and HV degrader | |
854 | //---------------------------------------------------- | |
855 | ||
856 | dm[0] = 0.; | |
857 | dm[1] = 360.; | |
858 | dm[2] = 4.; | |
859 | ||
860 | dm[3] = -250.; | |
861 | dm[4] = 74.4; | |
862 | dm[5] = 76.; | |
863 | ||
864 | dm[6] = -64.5; | |
865 | dm[7] = 50.; | |
866 | dm[8] = 76.; | |
867 | ||
868 | dm[9] = 64.5; | |
869 | dm[10] = 50.; | |
870 | dm[11] = 76.; | |
871 | ||
872 | dm[12] = 250.; | |
873 | dm[13] = 74.4; | |
874 | dm[14] = 76.; | |
875 | ||
876 | gMC->Gsvolu("TPVD", "PCON", idtmed[12], dm, 15); // CO2 | |
877 | ||
878 | // cone parts | |
879 | ||
880 | dm[0] = 0.; | |
881 | dm[1] = 360.; | |
882 | dm[2] = 2.; | |
883 | ||
884 | dm[3] = 64.5; | |
885 | dm[4] = 50.; | |
886 | dm[5] = 51.6; | |
887 | ||
888 | dm[6] = 250.; | |
889 | dm[7] = 74.4; | |
890 | dm[8] = 76.; | |
891 | ||
892 | ||
893 | gMC->Gsvolu("TIVC","PCON",idtmed[11],dm,9); // C-fibre | |
894 | ||
895 | gMC->Gspos("TIVC",1,"TPVD",0.,0.,0.,0,"ONLY"); | |
896 | gMC->Gspos("TIVC",2,"TPVD",0.,0.,0.,idrotm[nRotMat],"ONLY"); | |
897 | ||
898 | // barrel part | |
899 | ||
900 | dm[0] = 50.; | |
901 | dm[1] = 50.5; | |
902 | dm[2] = 32.25; | |
903 | ||
904 | gMC->Gsvolu("TIVB","TUBE",idtmed[9],dm,3); | |
905 | ||
906 | gMC->Gspos("TIVB",1,"TPVD",0.,0.,0.,0,"ONLY"); | |
907 | ||
908 | gMC->Gspos("TPVD",1,"ALIC",0.,0.,0.,0,"ONLY"); | |
909 | ||
910 | ||
911 | // --------------------------------------------------- | |
912 | // volumes ordering | |
913 | // --------------------------------------------------- | |
914 | ||
915 | gMC->Gsord("TGAS", 6); | |
916 | gMC->Gsord("TPSG", 6); | |
917 | ||
918 | ||
919 | ||
920 | } // end of function | |
921 | ||
922 | //_____________________________________________________________________________ | |
923 | void AliTPCv2::DrawDetector() | |
924 | { | |
925 | // | |
926 | // Draw a shaded view of the Time Projection Chamber version 1 | |
927 | // | |
928 | ||
929 | // Set everything unseen | |
930 | gMC->Gsatt("*", "seen", -1); | |
931 | // | |
932 | // Set ALIC mother transparent | |
933 | gMC->Gsatt("ALIC","SEEN",0); | |
934 | // | |
935 | // Set the volumes visible | |
936 | gMC->Gsatt("TPC","SEEN",0); | |
937 | gMC->Gsatt("TGAS","SEEN",0); | |
938 | gMC->Gsatt("TPSG","SEEN",0); | |
939 | gMC->Gsatt("TPHV","SEEN",1); | |
940 | gMC->Gsatt("TPMH","SEEN",1); | |
941 | gMC->Gsatt("TPEC","SEEN",0); | |
942 | gMC->Gsatt("TRCS","SEEN",1); | |
943 | gMC->Gsatt("TRCL","SEEN",1); | |
944 | gMC->Gsatt("TPWL","SEEN",1); | |
945 | gMC->Gsatt("TPWI","SEEN",1); | |
946 | gMC->Gsatt("TPWS","SEEN",1); | |
947 | gMC->Gsatt("TPW1","SEEN",1); | |
948 | gMC->Gsatt("TPS1","SEEN",1); | |
949 | gMC->Gsatt("TPS2","SEEN",1); | |
950 | gMC->Gsatt("TPG1","SEEN",1); | |
951 | gMC->Gsatt("TPG2","SEEN",1); | |
952 | gMC->Gsatt("TPWC","SEEN",1); | |
953 | gMC->Gsatt("TPSI","SEEN",1); | |
954 | gMC->Gsatt("TPSO","SEEN",1); | |
955 | gMC->Gsatt("TPCO","SEEN",1); | |
956 | gMC->Gsatt("TPOV","SEEN",1); | |
957 | gMC->Gsatt("TPVD","SEEN",1); | |
958 | // | |
959 | gMC->Gdopt("hide", "on"); | |
960 | gMC->Gdopt("shad", "on"); | |
961 | gMC->Gsatt("*", "fill", 7); | |
962 | gMC->SetClipBox("."); | |
963 | gMC->SetClipBox("*", 0, 1000, -1000, 1000, -1000, 1000); | |
964 | gMC->DefaultRange(); | |
965 | gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025); | |
966 | gMC->Gdhead(1111, "Time Projection Chamber"); | |
967 | gMC->Gdman(18, 4, "MAN"); | |
968 | gMC->Gdopt("hide","off"); | |
969 | } | |
970 | ||
971 | //_____________________________________________________________________________ | |
972 | void AliTPCv2::CreateMaterials() | |
973 | { | |
974 | // | |
975 | // Define materials for version 2 of the Time Projection Chamber | |
976 | // | |
977 | ||
978 | // | |
979 | // Increase maximum number of steps | |
980 | gMC->SetMaxNStep(30000); | |
981 | // | |
982 | AliTPC::CreateMaterials(); | |
983 | } | |
984 | ||
985 | //_____________________________________________________________________________ | |
986 | void AliTPCv2::Init() | |
987 | { | |
988 | // | |
989 | // Initialises version 2 of the TPC after that it has been built | |
990 | // | |
991 | Int_t *idtmed = fIdtmed->GetArray()-399; | |
992 | AliTPC::Init(); | |
993 | fIdSens1=gMC->VolId("TLGA"); // L-sector | |
994 | fIdSens2=gMC->VolId("TSGA"); // S-sector | |
995 | fIdSens3=gMC->VolId("TSST"); // strip - S-sector (not always used) | |
996 | fIdSens4=gMC->VolId("TLST"); // strip - S-sector (not always used) | |
997 | ||
998 | gMC->SetMaxNStep(30000); // max. number of steps increased | |
999 | ||
1000 | gMC->Gstpar(idtmed[403],"LOSS",5); | |
1001 | ||
1002 | printf("*** TPC version 2 initialized ***\n"); | |
1003 | printf("Maximum number of steps = %d\n",gMC->GetMaxNStep()); | |
1004 | ||
1005 | // | |
1006 | ||
1007 | } | |
1008 | ||
1009 | //_____________________________________________________________________________ | |
1010 | void AliTPCv2::StepManager() | |
1011 | { | |
1012 | // | |
1013 | // Called for every step in the Time Projection Chamber | |
1014 | // | |
1015 | ||
1016 | // | |
1017 | // parameters used for the energy loss calculations | |
1018 | // | |
1019 | const Float_t prim = 14.35; // number of primary collisions per 1 cm | |
1020 | const Float_t poti = 20.77e-9; // first ionization potential for Ne/CO2 | |
1021 | const Float_t w_ion = 35.97e-9; // energy for the ion-electron pair creation | |
1022 | ||
1023 | // const Float_t prim = 17.65; | |
1024 | // const Float_t poti = 19.02e-9; | |
1025 | // const Float_t w_ion = 33.06e-9; | |
1026 | ||
1027 | ||
1028 | const Float_t big = 1.e10; | |
1029 | ||
1030 | Int_t id,copy; | |
1031 | Float_t hits[4]; | |
1032 | Int_t vol[2]; | |
1033 | TClonesArray &lhits = *fHits; | |
1034 | TLorentzVector pos; | |
1035 | ||
1036 | AliTPCParam *fTPCParam = &(fDigParam->GetParam()); | |
1037 | ||
1038 | vol[1]=0; | |
1039 | ||
1040 | // | |
1041 | ||
1042 | gMC->SetMaxStep(big); | |
1043 | ||
1044 | if(!gMC->IsTrackAlive()) return; // particle has disappeared | |
1045 | ||
1046 | Float_t charge = gMC->TrackCharge(); | |
1047 | ||
1048 | if(TMath::Abs(charge)<=0.) return; // take only charged particles | |
1049 | ||
1050 | ||
1051 | id=gMC->CurrentVolID(copy); | |
1052 | ||
1053 | // Check the sensitive volume | |
1054 | ||
1055 | if(id == fIdSens1) | |
1056 | { | |
1057 | vol[0] = copy + fTPCParam->GetNInnerSector()-1; // L-sector number | |
1058 | } | |
1059 | else if(id == fIdSens2) | |
1060 | { | |
1061 | vol[0] = copy-1; // S-sector number | |
1062 | } | |
1063 | else if(id == fIdSens3 && gMC->IsTrackEntering()) | |
1064 | { | |
1065 | vol[1] = copy-1; // row number | |
1066 | id = gMC->CurrentVolOffID(1,copy); | |
1067 | vol[0] = copy-1; // sector number (S-sector) | |
1068 | ||
1069 | gMC->TrackPosition(pos); | |
1070 | hits[0]=pos[0]; | |
1071 | hits[1]=pos[1]; | |
1072 | hits[2]=pos[2]; | |
1073 | hits[3]=0.; // this hit has no energy loss | |
1074 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1075 | } | |
1076 | else if(id == fIdSens4 && gMC->IsTrackEntering()) | |
1077 | { | |
1078 | vol[1] = copy-1; // row number | |
1079 | id = gMC->CurrentVolOffID(1,copy); | |
1080 | vol[0] = copy+fTPCParam->GetNInnerSector()-1; // sector number (L-sector) | |
1081 | ||
1082 | gMC->TrackPosition(pos); | |
1083 | hits[0]=pos[0]; | |
1084 | hits[1]=pos[1]; | |
1085 | hits[2]=pos[2]; | |
1086 | hits[3]=0.; // this hit has no energy loss | |
1087 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1088 | } | |
1089 | else return; | |
1090 | ||
1091 | // | |
1092 | // charged particle is in the sensitive volume | |
1093 | // | |
1094 | ||
1095 | if(gMC->TrackStep() > 0) { | |
1096 | ||
1097 | Int_t nel = (Int_t)(((gMC->Edep())-poti)/w_ion) + 1; | |
1098 | nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV | |
1099 | ||
1100 | gMC->TrackPosition(pos); | |
1101 | hits[0]=pos[0]; | |
1102 | hits[1]=pos[1]; | |
1103 | hits[2]=pos[2]; | |
1104 | hits[3]=(Float_t)nel; | |
1105 | ||
1106 | // Add this hit | |
1107 | ||
1108 | new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits); | |
1109 | ||
1110 | } | |
1111 | ||
1112 | // Stemax calculation for the next step | |
1113 | ||
1114 | Float_t pp; | |
1115 | TLorentzVector mom; | |
1116 | gMC->TrackMomentum(mom); | |
1117 | Float_t ptot=mom.Rho(); | |
1118 | Float_t beta_gamma = ptot/gMC->TrackMass(); | |
1119 | ||
1120 | Int_t pid=gMC->TrackPid(); | |
1121 | if((pid==kElectron || pid==kPositron || pid==kGamma) && ptot > 0.002) | |
1122 | { | |
1123 | pp = prim*1.58; // electrons above 20 MeV/c are on the plateau! | |
1124 | } | |
1125 | else | |
1126 | { | |
1127 | pp=prim*BetheBloch(beta_gamma); | |
1128 | if(TMath::Abs(charge) > 1.) pp *= (charge*charge); | |
1129 | } | |
1130 | ||
1131 | Float_t random[1]; | |
1132 | gMC->Rndm(random,1); // good, old GRNDM from Geant3 | |
1133 | ||
1134 | Double_t rnd = (Double_t)random[0]; | |
1135 | ||
1136 | gMC->SetMaxStep(-TMath::Log(rnd)/pp); | |
1137 | ||
1138 | } | |
1139 | ||
1140 | //_____________________________________________________________________________ | |
1141 | Float_t AliTPCv2::BetheBloch(Float_t bg) | |
1142 | { | |
1143 | // | |
1144 | // Bethe-Bloch energy loss formula | |
1145 | // | |
1146 | const Double_t p1=0.76176e-1; | |
1147 | const Double_t p2=10.632; | |
1148 | const Double_t p3=0.13279e-4; | |
1149 | const Double_t p4=1.8631; | |
1150 | const Double_t p5=1.9479; | |
1151 | ||
1152 | Double_t dbg = (Double_t) bg; | |
1153 | ||
1154 | Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg); | |
1155 | ||
1156 | Double_t aa = TMath::Power(beta,p4); | |
1157 | Double_t bb = TMath::Power(1./dbg,p5); | |
1158 | ||
1159 | bb=TMath::Log(p3+bb); | |
1160 | ||
1161 | return ((Float_t)((p2-aa-bb)*p1/aa)); | |
1162 | } |