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14ab5373 | 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 | */ | |
19 | ||
20 | // Read background particles from a boundary source | |
21 | // Very specialized generator to simulate background from beam halo. | |
22 | // The input file is a text file specially prepared | |
23 | // for this purpose. | |
24 | // Author: andreas.morsch@cern.ch | |
25 | ||
26 | #include "AliGenHaloProtvino.h" | |
27 | #include "AliRun.h" | |
28 | #include "AliMC.h" | |
29 | #include "AliPDG.h" | |
30 | ||
31 | #include <TDatabasePDG.h> | |
32 | #include <stdlib.h> | |
33 | ||
34 | ClassImp(AliGenHaloProtvino) | |
35 | AliGenHaloProtvino::AliGenHaloProtvino() | |
36 | :AliGenerator(-1) | |
37 | { | |
38 | // Constructor | |
39 | fName="HaloProtvino"; | |
40 | fTitle="Halo from LHC Tunnel"; | |
41 | // | |
42 | // Read all particles | |
43 | fNpart=-1; | |
44 | fp=0; | |
45 | } | |
46 | ||
47 | AliGenHaloProtvino::AliGenHaloProtvino(Int_t npart) | |
48 | :AliGenerator(npart) | |
49 | { | |
50 | // Constructor | |
51 | fName="Halo"; | |
52 | fTitle="Halo from LHC Tunnel"; | |
53 | // | |
54 | // Read all particles | |
55 | fNpart=-1; | |
56 | fp=0; | |
57 | } | |
58 | ||
59 | AliGenHaloProtvino::AliGenHaloProtvino(const AliGenHaloProtvino & HaloProtvino) | |
60 | { | |
61 | // copy constructor | |
62 | } | |
63 | ||
64 | ||
65 | //____________________________________________________________ | |
66 | AliGenHaloProtvino::~AliGenHaloProtvino() | |
67 | { | |
68 | // Destructor | |
69 | } | |
70 | ||
71 | //____________________________________________________________ | |
72 | void AliGenHaloProtvino::Init() | |
73 | { | |
74 | // Initialisation | |
75 | } | |
76 | ||
77 | //____________________________________________________________ | |
78 | void AliGenHaloProtvino::Generate() | |
79 | { | |
80 | // Generate from input file | |
81 | FILE *fp = fopen(fFileName,"r"); | |
82 | if (fp) { | |
83 | printf("\n File %s opened for reading ! \n ", (char*) &fFileName); | |
84 | } else { | |
85 | printf("\n Opening of file %s failed ! \n ", (char*) &fFileName); | |
86 | } | |
87 | ||
88 | Float_t polar[3]= {0,0,0}; | |
89 | Float_t origin[3]; | |
90 | Float_t p[3], p0; | |
91 | Float_t ekin, wgt, tx, ty, tz, txy; | |
92 | Float_t zPrimary; | |
93 | Float_t amass; | |
94 | Int_t inuc; | |
95 | // | |
96 | Int_t ipart, ncols, nt; | |
97 | ||
98 | Int_t nread=0; | |
99 | origin[2]=2650; | |
100 | ||
101 | while(1) { | |
102 | ||
103 | ncols = fscanf(fp,"%f %d %d %f %f %f %f %f %f", | |
104 | &zPrimary, &inuc, &ipart, &wgt, | |
105 | &ekin, &origin[0], &origin[1], | |
106 | &tx, &ty); | |
107 | printf(" \n %f %d %d %f %f %f %f %f %f", | |
108 | zPrimary, inuc, ipart, wgt, | |
109 | ekin, origin[0], origin[1], | |
110 | tx, ty); | |
111 | ||
112 | if (ncols < 0) break; | |
113 | nread++; | |
114 | if (fNpart !=-1 && nread > fNpart) break; | |
115 | ||
116 | ||
117 | ||
118 | amass = TDatabasePDG::Instance()->GetParticle(ipart)->Mass(); | |
119 | ||
120 | // | |
121 | // Momentum vector | |
122 | // | |
123 | p0=sqrt(ekin*ekin + 2.*amass); | |
124 | ||
125 | txy=TMath::Sqrt(tx*tx+ty*ty); | |
126 | if (txy == 1.) { | |
127 | tz=0; | |
128 | } else { | |
129 | tz=-TMath::Sqrt(1.-txy); | |
130 | } | |
131 | ||
132 | p[0]=p0*tx; | |
133 | p[1]=p0*ty; | |
134 | p[2]=p0*tz; | |
135 | // | |
136 | // Origin: backtracking to tunnel entrance | |
137 | // | |
138 | Float_t zTunnelEntrance = -20.; | |
139 | origin[2] = zTunnelEntrance; | |
140 | Float_t dzBack = -1-zTunnelEntrance; | |
141 | Float_t dsBack = -dzBack/tz; | |
142 | ||
143 | origin[0]+=tx*dsBack; | |
144 | origin[1]+=ty*dsBack; | |
145 | ||
146 | // | |
147 | // | |
148 | // Particle weight | |
149 | ||
150 | ||
151 | fParentWeight=wgt*GassPressureWeight(zPrimary); | |
152 | gAlice->SetTrack(fTrackIt,-1,ipart,p,origin,polar,0,kPNoProcess,nt,fParentWeight); | |
153 | // | |
154 | // Assume particles come from two directions with same probability | |
155 | origin[2]=-origin[2]; | |
156 | p[2]=-p[2]; | |
157 | fParentWeight=wgt*GassPressureWeight(-zPrimary); | |
158 | gAlice->SetTrack(fTrackIt,-1,ipart,p,origin,polar,0,kPNoProcess,nt,fParentWeight); | |
159 | origin[2]=-origin[2]; | |
160 | p[2]=-p[2]; | |
161 | } | |
162 | } | |
163 | ||
164 | ||
165 | AliGenHaloProtvino& AliGenHaloProtvino::operator=(const AliGenHaloProtvino& rhs) | |
166 | { | |
167 | // Assignment operator | |
168 | return *this; | |
169 | } | |
170 | ||
171 | ||
172 | Float_t AliGenHaloProtvino::GassPressureWeight(Float_t zPrimary) | |
173 | { | |
174 | // Return z-dependent gasspressure weight | |
175 | // | |
176 | return 1.; | |
177 | } | |
178 | ||
179 | /* | |
180 | # Title: README file for the sources of IR8 machine induced background | |
181 | # Author: Vadim Talanov <Vadim.Talanov@cern.ch> | |
182 | # Modified: 12-12-2000 | |
183 | ||
184 | 0. Overview | |
185 | ||
186 | There are three files, named ring.one.beta.[01,10,50].m, which | |
187 | contain the lists of background particles, induced by proton losses | |
188 | upstream of IP8 in the LHC ring one, for the beta* values of 1, 10 | |
189 | and 50 m, respectively. | |
190 | ||
191 | 1. File contents | |
192 | ||
193 | Each line in the files contains the coordinates of particle track | |
194 | crossing with the infinite plane, positioned at z=-1m, together with | |
195 | the physical properties of corresponding particle, namely: | |
196 | ||
197 | S - S coordinate of the primary interaction vertex, cm; | |
198 | N - type of the gas nuclei at interaction, 1 is H, 2 - C and 3 - O; | |
199 | I - particle ID in PDG particle numbering scheme; | |
200 | W - particle weight; | |
201 | E - particle kinetic energy, GeV; | |
202 | X - x coordinate of the crossing point, cm; | |
203 | Y - y coordinate of the crossing point, cm; | |
204 | Dx - x direction cosine; | |
205 | Dy - y direction cosine. | |
206 | ||
207 | 2. Normalisation | |
208 | ||
209 | Each file is given per unity of linear density of proton inelastic | |
210 | interactions with the gas nuclei, [1 inelastic interaction/m]. | |
211 | ||
212 | # ~/vtalanov/public/README.mib: the end. | |
213 | ||
214 | */ | |
215 | ||
216 | ||
217 | ||
218 |