Removed the AliHLTPHOSValidCellDataStruct.h from Makefile.am
[u/mrichter/AliRoot.git] / LHC / AliLhcProcessIBS.cxx
CommitLineData
11141716 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
803d1ab0 16/* $Id$ */
11141716 17
21aa51f2 18//
19// Realisation of AliLhcProcess for the fast simulation of the
20// Intra Beam Scattering process
21// in transverse and longitudinal direction.
22// Author: Andreas Morsch
23// andreas.morsch@cern.ch
24//
25
11141716 26#include "AliLhcProcessIBS.h"
27#include "AliLHC.h"
28#include "AliLhcIRegion.h"
29#include "AliLhcBeam.h"
30
31#include <TF1.h>
32#include <TMath.h>
33#include <TCanvas.h>
34#include <TGraph.h>
35#include <TMultiGraph.h>
36
37ClassImp(AliLhcProcessIBS)
38
39 Double_t func(Double_t *x, Double_t *par);
40
41AliLhcProcessIBS::AliLhcProcessIBS(AliLHC* lhc, const char* name, const char* title)
64eb707f 42 :AliLhcProcess(lhc,name,title),
43 fCrossSection(0.),
44 fIRegions(0),
45 fTaux(0.),
46 fTaue(0.),
47 fTauxArray(0),
48 fTaueArray(0)
11141716 49{
50// Constructor
51}
52
64eb707f 53AliLhcProcessIBS::AliLhcProcessIBS(const AliLhcProcessIBS& ibs):
54 AliLhcProcess(ibs),
55 fCrossSection(0.),
56 fIRegions(0),
57 fTaux(0.),
58 fTaue(0.),
59 fTauxArray(0),
60 fTaueArray(0)
61{
62// Copy Constructor
63}
64
11141716 65
66AliLhcProcessIBS::~AliLhcProcessIBS()
67{
68// Destructor
69
70}
71
72void AliLhcProcessIBS::Init()
73{
74 // Initialization
75 const Float_t r0=1.535e-16;
76
77 printf("\n Initializing Process %s", GetName());
78 printf("\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^");
79
80 fIRegions = fAccelerator->IRegions();
81
82 for (Int_t i = 0; i < 2; i++) {
83 fBeam[i] = fAccelerator->Beam(i);
84 fR[i] = r0*fBeam[i]->Z()*fBeam[i]->Z()/fBeam[i]->A();
85 fE[i] = 0.938*fBeam[i]->A();
86 }
87}
88
89void AliLhcProcessIBS::Evolve(Float_t dt)
90{
21aa51f2 91//
92// Evolve by one time step dt
11141716 93 printf("\n Here process %s %f:", GetName(), dt);
94 for (Int_t i=0; i<2; i++) {
95 // Density
96 Float_t sige = fBeam[i]->EnergySpread();
97 Float_t avbeta = fAccelerator->AverageBeta();
98 Float_t avd = fAccelerator->AverageDisp();
99
100 Float_t gamma = fBeam[i]->Gamma();
101 Float_t epsx = fBeam[i]->Emittance()*gamma;
102 Float_t epsy = epsx;
103 Float_t epse = fBeam[i]->LongEmittance();
104 Float_t sigxb = TMath::Sqrt(epsx/gamma*avbeta);
105 Float_t sigx = TMath::Sqrt(sigxb*sigxb+(avd*avd*sige*sige));
106 Float_t ssigx = TMath::Sqrt(epsx/gamma/avbeta);
107 Float_t sigy = sigx;
108 Float_t ssigy = ssigx;
109
110 Float_t asd = fBeam[i]->N()*fR[i]*fR[i]*fE[i]/
111 (16.*TMath::Pi()*gamma*epsx*epsy*epse);
112
113 // impact parameter
114 Float_t d = sige*avd/sigx;
115 //
116 Float_t at = sige*TMath::Sqrt(1.-d*d)/(gamma*ssigx);
117 Float_t bt = sige*TMath::Sqrt(1.-d*d)/(gamma*ssigy);
118 Float_t ct = sige*TMath::Sqrt(1.-d*d)*TMath::Sqrt(4.*sigy/fR[i]);
119 //
120 Double_t par[3];
121 par[0] = at;
122 par[1] = bt;
123 par[2] = ct;
124 TF1 *fct = new TF1("func",func, 0., 1., 3);
125
126 Float_t f = (Float_t) 8.0*TMath::Pi()*
127 fct->Integral(0., 1., par, 1.e-5);
128 //
129 fTaux = 1./(asd*f*(d*d-at*at/2.));
130 fTaue = 1./(asd*f*(1.-d*d));
131 // printf("\n taux, taue %f %f", taux, taue);
132 // Float_t tauy = -2./at*at/asd/f;
133 fBeam[i]->IncreaseEmittance(dt/fTaux, dt/fTaue);
134 }
135
136}
137
138void AliLhcProcessIBS::SetMonitor(Int_t n)
139{
140 // Initialize Monitor
141 if (fTauxArray) delete fTauxArray;
142 if (fTaueArray) delete fTaueArray;
143 fTauxArray = new Float_t[n];
144 fTaueArray = new Float_t[n];
145 fNmax = n;
146}
147
148void AliLhcProcessIBS::Record()
149{
150 // Record monitor quantities
151 fTauxArray[fAccelerator->Nt()] = fTaux/3600.;
152 fTaueArray[fAccelerator->Nt()] = fTaue/3600.;
153}
154
155
156void AliLhcProcessIBS::DrawPlots()
157{
158 // Draw monitor plots
159 Float_t* t = fAccelerator->TimeA();
160
161 TH1 *t1 = new TH1F("t1","Hor. IBS growth time",fNmax,0,t[fNmax]);
162 t1->SetMinimum(0);
163 t1->SetMaximum(fTauxArray[fNmax]*1.1);
164 t1->SetStats(0);
165 t1->GetXaxis()->SetTitle("t (h)");
166 t1->GetYaxis()->SetTitle("tau_x (t)");
167
168 TH1 *t2 = new TH1F("t2","Long. IBS growth time",fNmax,0,t[fNmax]);
169 t2->SetMinimum(0);
170 t2->SetMaximum(fTaueArray[fNmax]*1.1);
171 t2->SetStats(0);
172 t2->GetXaxis()->SetTitle("t (h)");
173 t2->GetYaxis()->SetTitle("tau_l (t)");
174
175 TGraph* grTaux = new TGraph(fNmax, fAccelerator->TimeA(), fTauxArray);
176 grTaux->SetHistogram(t1);
177
178 TGraph* grTaue = new TGraph(fNmax, fAccelerator->TimeA(), fTaueArray);
179 grTaue->SetHistogram(t2);
180 grTaue->SetLineStyle(2);
181
182 TMultiGraph* mg = new TMultiGraph();
183 mg->Add(grTaux);
184 mg->Add(grTaue);
185
186 TCanvas *c3 = new TCanvas("c3","IBS", 200, 10, 700, 500);
187 c3->SetGrid();
188 mg->Draw("AC");
189 mg->GetXaxis()->SetTitle("t (h)");
190 mg->GetYaxis()->SetTitle("IBS Growth Time (h)");
191 mg->Draw("AC");
192}
193
194
195
196
197
e76f229f 198AliLhcProcessIBS& AliLhcProcessIBS::operator=(const AliLhcProcessIBS & /*rhs*/)
11141716 199{
200// Assignment operator
201 return *this;
202}
203
204Double_t func(Double_t *x, Double_t *par)
205{
206 Double_t a = par[0];
207 Double_t b = par[1];
208 Double_t cc = par[2];
209
21aa51f2 210 const Double_t kbc = 0.5772;
11141716 211 Double_t xx = x[0];
212 Double_t x2=xx*xx;
213 Double_t x1=1.0-x2;
214 Double_t p=1.0/TMath::Sqrt(x2+a*a*x1);
215 Double_t q=1.0/TMath::Sqrt(x2+b*b*x1);
21aa51f2 216 return (1.0-3.0*x2)*p*q*(2.0*TMath::Log(0.5*cc*(p+q))-kbc);
11141716 217}
218