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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 | $Log$ | |
dffd31ef | 18 | Revision 1.12 2000/04/07 11:12:33 fca |
19 | G4 compatibility changes | |
20 | ||
875c717b | 21 | Revision 1.11 2000/03/22 13:42:26 fca |
22 | SetGenerator does not replace an existing generator, ResetGenerator does | |
23 | ||
ee1dd322 | 24 | Revision 1.10 2000/02/23 16:25:22 fca |
25 | AliVMC and AliGeant3 classes introduced | |
26 | ReadEuclid moved from AliRun to AliModule | |
27 | ||
b13db077 | 28 | Revision 1.9 1999/12/03 10:54:01 fca |
29 | Fix lego summary | |
30 | ||
00719c1b | 31 | Revision 1.8 1999/10/01 09:54:33 fca |
32 | Correct logics for Lego StepManager | |
33 | ||
f059c84a | 34 | Revision 1.7 1999/09/29 09:24:29 fca |
35 | Introduction of the Copyright and cvs Log | |
36 | ||
4c039060 | 37 | */ |
38 | ||
fe4da5cc | 39 | ////////////////////////////////////////////////////////////// |
40 | ////////////////////////////////////////////////////////////// | |
41 | // | |
42 | // Utility class to evaluate the material budget from | |
43 | // a given radius to the surface of an arbitrary cylinder | |
44 | // along radial directions from the centre: | |
45 | // | |
46 | // - radiation length | |
47 | // - Interaction length | |
48 | // - g/cm2 | |
49 | // | |
50 | // Geantinos are shot in the bins in the fNtheta bins in theta | |
51 | // and fNphi bins in phi with specified rectangular limits. | |
52 | // The statistics are accumulated per | |
53 | // fRadMin < r < fRadMax and <0 < z < fZMax | |
54 | // | |
55 | // To activate this option, you can do: | |
56 | // Root > gAlice.RunLego(); | |
57 | // or Root > .x menu.C then select menu item "RunLego" | |
58 | // Note that when calling gAlice->RunLego, an optional list | |
59 | // of arguments may be specified. | |
60 | // | |
61 | //Begin_Html | |
62 | /* | |
1439f98e | 63 | <img src="picts/alilego.gif"> |
fe4da5cc | 64 | */ |
65 | //End_Html | |
66 | // | |
67 | ////////////////////////////////////////////////////////////// | |
68 | ||
69 | #include "TMath.h" | |
1578254f | 70 | #include "AliLego.h" |
fe4da5cc | 71 | #include "AliRun.h" |
72 | #include "AliConst.h" | |
875c717b | 73 | #include "AliMC.h" |
fe4da5cc | 74 | |
75 | ClassImp(AliLego) | |
76 | ||
77 | ||
78 | //___________________________________________ | |
79 | AliLego::AliLego() | |
80 | { | |
81 | fHistRadl = 0; | |
82 | fHistAbso = 0; | |
83 | fHistGcm2 = 0; | |
84 | fHistReta = 0; | |
85 | } | |
86 | ||
87 | //___________________________________________ | |
b13db077 | 88 | AliLego::AliLego(const char *title, Int_t ntheta, Float_t themin, Float_t themax, |
89 | Int_t nphi, Float_t phimin, Float_t phimax, | |
90 | Float_t rmin, Float_t rmax, Float_t zmax) | |
91 | : TNamed("Lego Generator",title) | |
fe4da5cc | 92 | { |
b13db077 | 93 | // specify the angular limits and the size of the rectangular box |
94 | ||
95 | fGener = new AliLegoGenerator(ntheta, themin, themax, | |
96 | nphi, phimin, phimax, rmin, rmax, zmax); | |
97 | ||
ee1dd322 | 98 | gAlice->ResetGenerator(fGener); |
b13db077 | 99 | |
100 | Float_t etamin = -TMath::Log(TMath::Tan(TMath::Min((Double_t)themax*kDegrad/2,TMath::Pi()/2-1.e-10))); | |
101 | Float_t etamax = -TMath::Log(TMath::Tan(TMath::Max((Double_t)themin*kDegrad/2, 1.e-10))); | |
102 | ||
103 | fHistRadl = new TH2F("hradl","Radiation length map", | |
104 | nphi,phimin,phimax,ntheta,themin,themax); | |
105 | fHistAbso = new TH2F("habso","Interaction length map", | |
106 | nphi,phimin,phimax,ntheta,themin,themax); | |
107 | fHistGcm2 = new TH2F("hgcm2","g/cm2 length map", | |
108 | nphi,phimin,phimax,ntheta,themin,themax); | |
109 | fHistReta = new TH2F("hetar","Radiation length vs. eta", | |
110 | nphi,phimin,phimax,ntheta,etamin,etamax); | |
111 | ||
fe4da5cc | 112 | } |
113 | ||
114 | //___________________________________________ | |
115 | AliLego::~AliLego() | |
116 | { | |
117 | delete fHistRadl; | |
118 | delete fHistAbso; | |
119 | delete fHistGcm2; | |
120 | delete fHistReta; | |
121 | } | |
122 | ||
b13db077 | 123 | //___________________________________________ |
dffd31ef | 124 | void AliLego::BeginEvent() |
b13db077 | 125 | { |
b13db077 | 126 | // --- Set to 0 radiation length, absorption length and g/cm2 --- |
dffd31ef | 127 | fTotRadl = 0; |
128 | fTotAbso = 0; | |
129 | fTotGcm2 = 0; | |
130 | } | |
131 | ||
132 | //___________________________________________ | |
133 | void AliLego::FinishEvent() | |
134 | { | |
135 | Double_t thed, phid, eta; | |
136 | thed = fGener->CurTheta()*kRaddeg; | |
137 | phid = fGener->CurPhi()*kRaddeg; | |
138 | eta = -TMath::Log(TMath::Tan(TMath::Max( | |
b13db077 | 139 | TMath::Min((Double_t)(fGener->CurTheta())/2, |
140 | TMath::Pi()/2-1.e-10),1.e-10))); | |
141 | ||
dffd31ef | 142 | fHistRadl->Fill(phid,thed,fTotRadl); |
143 | fHistAbso->Fill(phid,thed,fTotAbso); | |
144 | fHistGcm2->Fill(phid,thed,fTotGcm2); | |
145 | fHistReta->Fill(phid,eta,fTotRadl); | |
b13db077 | 146 | } |
147 | ||
dffd31ef | 148 | //___________________________________________ |
149 | void AliLego::FinishRun() | |
150 | { | |
151 | // Store histograms in current Root file | |
152 | fHistRadl->Write(); | |
153 | fHistAbso->Write(); | |
154 | fHistGcm2->Write(); | |
155 | fHistReta->Write(); | |
156 | ||
157 | // Delete histograms from memory | |
158 | fHistRadl->Delete(); fHistRadl=0; | |
159 | fHistAbso->Delete(); fHistAbso=0; | |
160 | fHistGcm2->Delete(); fHistGcm2=0; | |
161 | fHistReta->Delete(); fHistReta=0; | |
162 | ||
163 | } | |
164 | ||
165 | ||
b13db077 | 166 | //___________________________________________ |
167 | void AliLego::StepManager() | |
168 | { | |
169 | // called from AliRun::Stepmanager from gustep. | |
170 | // Accumulate the 3 parameters step by step | |
171 | ||
172 | static Float_t t; | |
173 | Float_t a,z,dens,radl,absl; | |
174 | Int_t i; | |
175 | ||
176 | Float_t step = gMC->TrackStep(); | |
177 | ||
178 | Float_t vect[3], dir[3]; | |
179 | TLorentzVector pos, mom; | |
180 | ||
181 | gMC->TrackPosition(pos); | |
182 | gMC->TrackMomentum(mom); | |
183 | gMC->CurrentMaterial(a,z,dens,radl,absl); | |
184 | ||
185 | if (z < 1) return; | |
186 | ||
187 | // --- See if we have to stop now | |
188 | if (TMath::Abs(pos[2]) > fGener->ZMax() || | |
189 | pos[0]*pos[0] +pos[1]*pos[1] > fGener->RadMax()*fGener->RadMax()) { | |
190 | if (gMC->TrackLength()) { | |
191 | // Not the first step, add past contribution | |
192 | fTotAbso += t/absl; | |
193 | fTotRadl += t/radl; | |
194 | fTotGcm2 += t*dens; | |
195 | } | |
196 | gMC->StopTrack(); | |
197 | return; | |
198 | } | |
199 | ||
200 | // --- See how long we have to go | |
201 | for(i=0;i<3;++i) { | |
202 | vect[i]=pos[i]; | |
203 | dir[i]=mom[i]; | |
204 | } | |
205 | ||
206 | t = fGener->PropagateCylinder(vect,dir,fGener->RadMax(),fGener->ZMax()); | |
207 | ||
208 | if(step) { | |
209 | fTotAbso += step/absl; | |
210 | fTotRadl += step/radl; | |
211 | fTotGcm2 += step*dens; | |
212 | } | |
213 | } | |
214 | ||
215 | ClassImp(AliLegoGenerator) | |
216 | ||
217 | //___________________________________________ | |
218 | AliLegoGenerator::AliLegoGenerator(Int_t ntheta, Float_t themin, | |
219 | Float_t themax, Int_t nphi, | |
220 | Float_t phimin, Float_t phimax, | |
221 | Float_t rmin, Float_t rmax, Float_t zmax) : | |
222 | AliGenerator(0), fRadMin(rmin), fRadMax(rmax), fZMax(zmax), fNtheta(ntheta), | |
223 | fNphi(nphi), fThetaBin(ntheta), fPhiBin(-1), fCurTheta(0), fCurPhi(0) | |
224 | ||
225 | { | |
226 | SetPhiRange(phimin,phimax); | |
227 | SetThetaRange(themin,themax); | |
228 | SetName("Lego"); | |
229 | } | |
230 | ||
231 | ||
fe4da5cc | 232 | //___________________________________________ |
b13db077 | 233 | void AliLegoGenerator::Generate() |
fe4da5cc | 234 | { |
235 | // Create a geantino with kinematics corresponding to the current | |
236 | // bins in theta and phi. | |
237 | ||
1578254f | 238 | // |
239 | // Rootinos are 0 | |
240 | const Int_t mpart = 0; | |
fe4da5cc | 241 | Float_t orig[3], pmom[3]; |
242 | Float_t t, cost, sint, cosp, sinp; | |
243 | ||
b13db077 | 244 | // Prepare for next step |
245 | if(fThetaBin>=fNtheta-1) | |
246 | if(fPhiBin>=fNphi-1) { | |
247 | Warning("Generate","End of Lego Generation"); | |
248 | return; | |
249 | } else { | |
250 | fPhiBin++; | |
251 | printf("Generating rays in phi bin:%d\n",fPhiBin); | |
252 | fThetaBin=0; | |
253 | } else fThetaBin++; | |
fe4da5cc | 254 | |
b13db077 | 255 | fCurTheta = (fThetaMin+(fThetaBin+0.5)*(fThetaMax-fThetaMin)/fNtheta); |
256 | fCurPhi = (fPhiMin+(fPhiBin+0.5)*(fPhiMax-fPhiMin)/fNphi); | |
fe4da5cc | 257 | cost = TMath::Cos(fCurTheta); |
258 | sint = TMath::Sin(fCurTheta); | |
259 | cosp = TMath::Cos(fCurPhi); | |
260 | sinp = TMath::Sin(fCurPhi); | |
b13db077 | 261 | |
fe4da5cc | 262 | pmom[0] = cosp*sint; |
263 | pmom[1] = sinp*sint; | |
264 | pmom[2] = cost; | |
b13db077 | 265 | |
266 | // --- Where to start | |
fe4da5cc | 267 | orig[0] = orig[1] = orig[2] = 0; |
268 | Float_t dalicz = 3000; | |
269 | if (fRadMin > 0) { | |
b13db077 | 270 | t = PropagateCylinder(orig,pmom,fRadMin,dalicz); |
271 | orig[0] = pmom[0]*t; | |
272 | orig[1] = pmom[1]*t; | |
273 | orig[2] = pmom[2]*t; | |
274 | if (TMath::Abs(orig[2]) > fZMax) return; | |
fe4da5cc | 275 | } |
b13db077 | 276 | |
fe4da5cc | 277 | Float_t polar[3]={0.,0.,0.}; |
278 | Int_t ntr; | |
279 | gAlice->SetTrack(1, 0, mpart, pmom, orig, polar, 0, "LEGO ray", ntr); | |
fe4da5cc | 280 | |
281 | } | |
282 | ||
283 | //___________________________________________ | |
b13db077 | 284 | Float_t AliLegoGenerator::PropagateCylinder(Float_t *x, Float_t *v, Float_t r, Float_t z) |
fe4da5cc | 285 | { |
286 | // Propagate to cylinder from inside | |
287 | ||
288 | Double_t hnorm, sz, t, t1, t2, t3, sr; | |
289 | Double_t d[3]; | |
290 | const Float_t kSmall = 1e-8; | |
291 | const Float_t kSmall2 = kSmall*kSmall; | |
292 | ||
293 | // ---> Find intesection with Z planes | |
294 | d[0] = v[0]; | |
295 | d[1] = v[1]; | |
296 | d[2] = v[2]; | |
297 | hnorm = TMath::Sqrt(1/(d[0]*d[0]+d[1]*d[1]+d[2]*d[2])); | |
298 | d[0] *= hnorm; | |
299 | d[1] *= hnorm; | |
300 | d[2] *= hnorm; | |
301 | if (d[2] > kSmall) sz = (z-x[2])/d[2]; | |
302 | else if (d[2] < -kSmall) sz = -(z+x[2])/d[2]; | |
303 | else sz = 1.e10; // ---> Direction parallel to X-Y, no intersection | |
304 | ||
305 | // ---> Intersection with cylinders | |
306 | // Intersection point (x,y,z) | |
307 | // (x,y,z) is on track : x=X(1)+t*D(1) | |
308 | // y=X(2)+t*D(2) | |
309 | // z=X(3)+t*D(3) | |
310 | // (x,y,z) is on cylinder : x**2 + y**2 = R**2 | |
311 | // | |
312 | // (D(1)**2+D(2)**2)*t**2 | |
313 | // +2.*(X(1)*D(1)+X(2)*D(2))*t | |
314 | // +X(1)**2+X(2)**2-R**2=0 | |
315 | // ---> Solve second degree equation | |
316 | t1 = d[0]*d[0] + d[1]*d[1]; | |
317 | if (t1 <= kSmall2) { | |
318 | t = sz; // ---> Track parallel to the z-axis, take distance to planes | |
319 | } else { | |
320 | t2 = x[0]*d[0] + x[1]*d[1]; | |
321 | t3 = x[0]*x[0] + x[1]*x[1]; | |
322 | // ---> It should be positive, but there may be numerical problems | |
323 | sr = (t2 +TMath::Sqrt(TMath::Max(t2*t2-(t3-r*r)*t1,0.)))/t1; | |
324 | // ---> Find minimum distance between planes and cylinder | |
325 | t = TMath::Min(sz,sr); | |
326 | } | |
327 | return t; | |
328 | } | |
329 |