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1 | /************************************************************************** | |
2 | * Copyright(c) 2004, 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 | /* $Id$ */ | |
17 | ||
18 | //__________________________________________________________________ | |
19 | // | |
20 | // Utility class to help implement collection of FMD modules into | |
21 | // rings. This is used by AliFMDDetector and AliFMDGeometry. | |
22 | // | |
23 | // The AliFMDGeometry object owns the AliFMDRing objects, and the | |
24 | // AliFMDDetector objects reference these. That is, the AliFMDRing | |
25 | // objects are share amoung the AliFMDDetector objects. | |
26 | // | |
27 | // Latest changes by Christian Holm Christensen | |
28 | // | |
29 | ||
30 | #include <AliLog.h> // ALILOG_H | |
31 | #include "AliFMDRing.h" // ALIFMDRING_H | |
32 | #include <TMath.h> // ROOT_TMath | |
33 | #include <TVector2.h> // ROOT_TVector2 | |
34 | ||
35 | //==================================================================== | |
36 | ClassImp(AliFMDRing) | |
37 | #if 0 | |
38 | ; // This is here to keep Emacs for indenting the next line | |
39 | #endif | |
40 | ||
41 | //____________________________________________________________________ | |
42 | AliFMDRing::AliFMDRing(Char_t id) | |
43 | : TNamed(Form("FMD%c", id), "Forward multiplicity ring"), | |
44 | fId(id), | |
45 | fVerticies(0) | |
46 | { | |
47 | // CTOR | |
48 | SetBondingWidth(); | |
49 | SetWaferRadius(); | |
50 | SetSiThickness(); | |
51 | SetLegRadius(); | |
52 | SetLegLength(); | |
53 | SetLegOffset(); | |
54 | SetModuleSpacing(); | |
55 | SetPrintboardThickness(); | |
56 | SetCopperThickness(); | |
57 | SetChipThickness(); | |
58 | SetSpacing(); | |
59 | ||
60 | if (fId == 'I' || fId == 'i') { | |
61 | SetLowR(4.3); | |
62 | SetHighR(17.2); | |
63 | SetTheta(36/2); | |
64 | SetNStrips(512); | |
65 | } | |
66 | else if (fId == 'O' || fId == 'o') { | |
67 | SetLowR(15.6); | |
68 | SetHighR(28.0); | |
69 | SetTheta(18/2); | |
70 | SetNStrips(256); | |
71 | } | |
72 | } | |
73 | ||
74 | //____________________________________________________________________ | |
75 | void | |
76 | AliFMDRing::Init() | |
77 | { | |
78 | // Initialize | |
79 | Double_t tanTheta = TMath::Tan(fTheta * TMath::Pi() / 180.); | |
80 | Double_t tanTheta2 = TMath::Power(tanTheta,2); | |
81 | Double_t r2 = TMath::Power(fWaferRadius,2); | |
82 | Double_t yA = tanTheta * fLowR; | |
83 | Double_t lr2 = TMath::Power(fLowR, 2); | |
84 | Double_t hr2 = TMath::Power(fHighR,2); | |
85 | Double_t xD = fLowR + TMath::Sqrt(r2 - tanTheta2 * lr2); | |
86 | Double_t xD2 = TMath::Power(xD,2); | |
87 | Double_t yB = TMath::Sqrt(r2 - hr2 + 2 * fHighR * xD - xD2); | |
88 | Double_t xC = ((xD + TMath::Sqrt(-tanTheta2 * xD2 + r2 | |
89 | + r2 * tanTheta2)) | |
90 | / (1 + tanTheta2)); | |
91 | Double_t yC = tanTheta * xC; | |
92 | ||
93 | fVerticies.Expand(6); | |
94 | fVerticies.AddAt(new TVector2(fLowR, -yA), 0); | |
95 | fVerticies.AddAt(new TVector2(xC, -yC), 1); | |
96 | fVerticies.AddAt(new TVector2(fHighR, -yB), 2); | |
97 | fVerticies.AddAt(new TVector2(fHighR, yB), 3); | |
98 | fVerticies.AddAt(new TVector2(xC, yC), 4); | |
99 | fVerticies.AddAt(new TVector2(fLowR, yA), 5); | |
100 | ||
101 | // A's length. Corresponds to distance from nominal beam line to the | |
102 | // cornor of the active silicon element. | |
103 | fMinR = GetVertex(5)->Mod(); | |
104 | // A's length. Corresponds to distance from nominal beam line to the | |
105 | // cornor of the active silicon element. | |
106 | fMaxR = fHighR; | |
107 | ||
108 | fRingDepth = (fSiThickness + fPrintboardThickness | |
109 | + fCopperThickness + fChipThickness | |
110 | + fLegLength + fModuleSpacing + fSpacing); | |
111 | } | |
112 | ||
113 | //____________________________________________________________________ | |
114 | TVector2* | |
115 | AliFMDRing::GetVertex(Int_t i) const | |
116 | { | |
117 | // Get the i'th vertex of polygon shape | |
118 | return static_cast<TVector2*>(fVerticies.At(i)); | |
119 | } | |
120 | ||
121 | //____________________________________________________________________ | |
122 | void | |
123 | AliFMDRing::Detector2XYZ(UShort_t sector, | |
124 | UShort_t strip, | |
125 | Double_t& x, | |
126 | Double_t& y, | |
127 | Double_t& z) const | |
128 | { | |
129 | // Translate detector coordinates (this,sector,strip) to global | |
130 | // coordinates (x,y,z) | |
131 | if (sector >= GetNSectors()) { | |
132 | Error("Detector2XYZ", "Invalid sector number %d (>=%d) in ring %c", | |
133 | sector, GetNSectors(), fId); | |
134 | return; | |
135 | } | |
136 | if (strip >= GetNStrips()) { | |
137 | Error("Detector2XYZ", "Invalid strip number %d (>=%d)", | |
138 | strip, GetNStrips(), fId); | |
139 | return; | |
140 | } | |
141 | Double_t phi = Float_t(sector + .5) / GetNSectors() * 2 * TMath::Pi(); | |
142 | Double_t r = Float_t(strip + .5) / GetNStrips() * (fHighR - fLowR) + fLowR; | |
143 | x = r * TMath::Cos(phi); | |
144 | y = r * TMath::Sin(phi); | |
145 | if (((sector / 2) % 2) == 1) | |
146 | z += TMath::Sign(fModuleSpacing, z); | |
147 | } | |
148 | ||
149 | //____________________________________________________________________ | |
150 | Bool_t | |
151 | AliFMDRing::XYZ2Detector(Double_t x, | |
152 | Double_t y, | |
153 | Double_t z, | |
154 | UShort_t& sector, | |
155 | UShort_t& strip) const | |
156 | { | |
157 | // Translate global coordinates (x,y,z) to detector coordinates | |
158 | // (this,sector,strip) | |
159 | sector = strip = 0; | |
160 | Double_t r = TMath::Sqrt(x * x + y * y); | |
161 | Int_t str = Int_t((r - fMinR) / GetPitch()); | |
162 | if (str < 0 || str >= GetNStrips()) return kFALSE; | |
163 | ||
164 | Double_t phi = TMath::ATan2(y, x) * 180. / TMath::Pi(); | |
165 | if (phi < 0) phi = 360. + phi; | |
166 | Int_t sec = Int_t(phi / fTheta); | |
167 | if (sec < 0 || sec >= GetNSectors()) return kFALSE; | |
168 | if ((sec / 2) % 2 == 1) { | |
169 | if (TMath::Abs(z - TMath::Sign(fModuleSpacing, z)) >= 0.01) | |
170 | return kFALSE; | |
171 | } | |
172 | else if (TMath::Abs(z) >= 0.01) return kFALSE; | |
173 | ||
174 | strip = str; | |
175 | sector = sec; | |
176 | return kTRUE; | |
177 | } | |
178 | ||
179 | ||
180 | // | |
181 | // EOF | |
182 | // |