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02a27b50 | 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 | /* $Id$ */ | |
16 | /** @file AliFMDBaseDigitizer.cxx | |
17 | @author Christian Holm Christensen <cholm@nbi.dk> | |
18 | @date Mon Mar 27 12:38:26 2006 | |
19 | @brief FMD Digitizers implementation | |
20 | @ingroup FMD_sim | |
21 | */ | |
22 | ////////////////////////////////////////////////////////////////////////////// | |
23 | // | |
24 | // This class contains the procedures simulation ADC signal for the | |
25 | // Forward Multiplicity detector : Hits->Digits and Hits->SDigits | |
26 | // | |
27 | // Digits consists of | |
28 | // - Detector # | |
29 | // - Ring ID | |
30 | // - Sector # | |
31 | // - Strip # | |
32 | // - ADC count in this channel | |
33 | // | |
34 | // Digits consists of | |
35 | // - Detector # | |
36 | // - Ring ID | |
37 | // - Sector # | |
38 | // - Strip # | |
39 | // - Total energy deposited in the strip | |
40 | // - ADC count in this channel | |
41 | // | |
42 | // As the Digits and SDigits have so much in common, the classes | |
43 | // AliFMDDigitizer and AliFMDSDigitizer are implemented via a base | |
44 | // class AliFMDBaseDigitizer. | |
45 | // | |
46 | // +---------------------+ | |
47 | // | AliFMDBaseDigitizer | | |
48 | // +---------------------+ | |
49 | // ^ | |
50 | // | | |
51 | // +----------+---------+ | |
52 | // | | | |
53 | // +-----------------+ +------------------+ | |
54 | // | AliFMDDigitizer | | AliFMDSDigitizer | | |
55 | // +-----------------+ +------------------+ | |
56 | // | |
57 | // These classes has several paramters: | |
58 | // | |
59 | // fPedestal | |
60 | // fPedestalWidth | |
61 | // (Only AliFMDDigitizer) | |
62 | // Mean and width of the pedestal. The pedestal is simulated | |
63 | // by a Guassian, but derived classes my override MakePedestal | |
64 | // to simulate it differently (or pick it up from a database). | |
65 | // | |
66 | // fVA1MipRange | |
67 | // The dymamic MIP range of the VA1_ALICE pre-amplifier chip | |
68 | // | |
69 | // fAltroChannelSize | |
70 | // The largest number plus one that can be stored in one | |
71 | // channel in one time step in the ALTRO ADC chip. | |
72 | // | |
73 | // fSampleRate | |
74 | // How many times the ALTRO ADC chip samples the VA1_ALICE | |
75 | // pre-amplifier signal. The VA1_ALICE chip is read-out at | |
76 | // 10MHz, while it's possible to drive the ALTRO chip at | |
77 | // 25MHz. That means, that the ALTRO chip can have time to | |
78 | // sample each VA1_ALICE signal up to 2 times. Although it's | |
79 | // not certain this feature will be used in the production, | |
80 | // we'd like have the option, and so it should be reflected in | |
81 | // the code. | |
82 | // | |
83 | // | |
84 | // The shaping function of the VA1_ALICE is generally given by | |
85 | // | |
86 | // f(x) = A(1 - exp(-Bx)) | |
87 | // | |
88 | // where A is the total charge collected in the pre-amp., and B is a | |
89 | // paramter that depends on the shaping time of the VA1_ALICE circut. | |
90 | // | |
91 | // When simulating the shaping function of the VA1_ALICe | |
92 | // pre-amp. chip, we have to take into account, that the shaping | |
93 | // function depends on the previous value of read from the pre-amp. | |
94 | // | |
95 | // That results in the following algorithm: | |
96 | // | |
97 | // last = 0; | |
98 | // FOR charge IN pre-amp. charge train DO | |
99 | // IF last < charge THEN | |
100 | // f(t) = (charge - last) * (1 - exp(-B * t)) + last | |
101 | // ELSE | |
102 | // f(t) = (last - charge) * exp(-B * t) + charge) | |
103 | // ENDIF | |
104 | // FOR i IN # samples DO | |
105 | // adc_i = f(i / (# samples)) | |
106 | // DONE | |
107 | // last = charge | |
108 | // DONE | |
109 | // | |
110 | // Here, | |
111 | // | |
112 | // pre-amp. charge train | |
113 | // is a series of 128 charges read from the VA1_ALICE chip | |
114 | // | |
115 | // # samples | |
116 | // is the number of times the ALTRO ADC samples each of the 128 | |
117 | // charges from the pre-amp. | |
118 | // | |
119 | // Where Q is the total charge collected by the VA1_ALICE | |
120 | // pre-amplifier. Q is then given by | |
121 | // | |
122 | // E S | |
123 | // Q = - - | |
124 | // e R | |
125 | // | |
126 | // where E is the total energy deposited in a silicon strip, R is the | |
127 | // dynamic range of the VA1_ALICE pre-amp (fVA1MipRange), e is the | |
128 | // energy deposited by a single MIP, and S ALTRO channel size in each | |
129 | // time step (fAltroChannelSize). | |
130 | // | |
131 | // The energy deposited per MIP is given by | |
132 | // | |
133 | // e = M * rho * w | |
134 | // | |
135 | // where M is the universal number 1.664, rho is the density of | |
136 | // silicon, and w is the depth of the silicon sensor. | |
137 | // | |
138 | // The final ADC count is given by | |
139 | // | |
140 | // C' = C + P | |
141 | // | |
142 | // where P is the (randomized) pedestal (see MakePedestal) | |
143 | // | |
144 | // This class uses the class template AliFMDMap<Type> to make an | |
145 | // internal cache of the energy deposted of the hits. The class | |
146 | // template is instantasized as | |
147 | // | |
148 | // typedef AliFMDMap<std::pair<Float_t, UShort_t> > AliFMDEdepMap; | |
149 | // | |
150 | // The first member of the values is the summed energy deposition in a | |
151 | // given strip, while the second member of the values is the number of | |
152 | // hits in a given strip. Using the second member, it's possible to | |
153 | // do some checks on just how many times a strip got hit, and what | |
154 | // kind of error we get in our reconstructed hits. Note, that this | |
155 | // information is currently not written to the digits tree. I think a | |
156 | // QA (Quality Assurance) digit tree is better suited for that task. | |
157 | // However, the information is there to be used in the future. | |
158 | // | |
159 | // | |
160 | // Latest changes by Christian Holm Christensen | |
161 | // | |
162 | ////////////////////////////////////////////////////////////////////////////// | |
163 | ||
164 | // /1 | |
165 | // | A(-1 + B + exp(-B)) | |
166 | // | f(x) dx = ------------------- = 1 | |
167 | // | B | |
168 | // / 0 | |
169 | // | |
170 | // and B is the a parameter defined by the shaping time (fShapingTime). | |
171 | // | |
172 | // Solving the above equation, for A gives | |
173 | // | |
174 | // B | |
175 | // A = ---------------- | |
176 | // -1 + B + exp(-B) | |
177 | // | |
178 | // So, if we define the function g: [0,1] -> [0:1] by | |
179 | // | |
180 | // / v | |
181 | // | Bu + exp(-Bu) - Bv - exp(-Bv) | |
182 | // g(u,v) = | f(x) dx = -A ----------------------------- | |
183 | // | B | |
184 | // / u | |
185 | // | |
186 | // we can evaluate the ALTRO sample of the VA1_ALICE pre-amp between | |
187 | // any two times (u, v), by | |
188 | // | |
189 | // | |
190 | // B Bu + exp(-Bu) - Bv - exp(-Bv) | |
191 | // C = Q g(u,v) = - Q ---------------- ----------------------------- | |
192 | // -1 + B + exp(-B) B | |
193 | // | |
194 | // Bu + exp(-Bu) - Bv - exp(-Bv) | |
195 | // = - Q ----------------------------- | |
196 | // -1 + B + exp(-B) | |
197 | // | |
198 | ||
090026bf | 199 | #include <TMath.h> |
02a27b50 | 200 | #include <TTree.h> // ROOT_TTree |
201 | //#include <TRandom.h> // ROOT_TRandom | |
f95a63c4 | 202 | // #include <AliLog.h> // ALILOG_H |
203 | #include "AliFMDDebug.h" // Better debug macros | |
02a27b50 | 204 | #include "AliFMDBaseDigitizer.h" // ALIFMDDIGITIZER_H |
205 | #include "AliFMD.h" // ALIFMD_H | |
206 | #include "AliFMDGeometry.h" // ALIFMDGEOMETRY_H | |
207 | #include "AliFMDDetector.h" // ALIFMDDETECTOR_H | |
208 | #include "AliFMDRing.h" // ALIFMDRING_H | |
209 | #include "AliFMDHit.h" // ALIFMDHIT_H | |
6169f936 | 210 | // #include "AliFMDDigit.h" // ALIFMDDIGIT_H |
02a27b50 | 211 | #include "AliFMDParameters.h" // ALIFMDPARAMETERS_H |
6169f936 | 212 | // #include <AliRunDigitizer.h> // ALIRUNDIGITIZER_H |
02a27b50 | 213 | //#include <AliRun.h> // ALIRUN_H |
214 | #include <AliLoader.h> // ALILOADER_H | |
42f1b2f5 | 215 | #include <AliRun.h> // ALILOADER_H |
02a27b50 | 216 | #include <AliRunLoader.h> // ALIRUNLOADER_H |
217 | ||
218 | //==================================================================== | |
219 | ClassImp(AliFMDBaseDigitizer) | |
220 | #if 0 | |
221 | ; // This is here to keep Emacs for indenting the next line | |
222 | #endif | |
223 | ||
224 | //____________________________________________________________________ | |
225 | AliFMDBaseDigitizer::AliFMDBaseDigitizer() | |
b5ee4425 | 226 | : fRunLoader(0), |
227 | fEdep(AliFMDMap::kMaxDetectors, | |
228 | AliFMDMap::kMaxRings, | |
229 | AliFMDMap::kMaxSectors, | |
230 | AliFMDMap::kMaxStrips), | |
2aeec17d | 231 | fShapingTime(6) |
02a27b50 | 232 | { |
42f1b2f5 | 233 | AliFMDDebug(1, ("Constructed")); |
02a27b50 | 234 | // Default ctor - don't use it |
235 | } | |
236 | ||
237 | //____________________________________________________________________ | |
238 | AliFMDBaseDigitizer::AliFMDBaseDigitizer(AliRunDigitizer* manager) | |
239 | : AliDigitizer(manager, "AliFMDBaseDigitizer", "FMD Digitizer base class"), | |
240 | fRunLoader(0), | |
241 | fEdep(AliFMDMap::kMaxDetectors, | |
242 | AliFMDMap::kMaxRings, | |
243 | AliFMDMap::kMaxSectors, | |
b5ee4425 | 244 | AliFMDMap::kMaxStrips), |
2aeec17d | 245 | fShapingTime(6) |
02a27b50 | 246 | { |
247 | // Normal CTOR | |
42f1b2f5 | 248 | AliFMDDebug(1, ("Constructed")); |
02a27b50 | 249 | SetShapingTime(); |
250 | } | |
251 | ||
252 | //____________________________________________________________________ | |
253 | AliFMDBaseDigitizer::AliFMDBaseDigitizer(const Char_t* name, | |
254 | const Char_t* title) | |
255 | : AliDigitizer(name, title), | |
256 | fRunLoader(0), | |
257 | fEdep(AliFMDMap::kMaxDetectors, | |
258 | AliFMDMap::kMaxRings, | |
259 | AliFMDMap::kMaxSectors, | |
322be683 | 260 | AliFMDMap::kMaxStrips), |
261 | fShapingTime(6) | |
02a27b50 | 262 | { |
263 | // Normal CTOR | |
42f1b2f5 | 264 | AliFMDDebug(1, (" Constructed")); |
02a27b50 | 265 | SetShapingTime(); |
266 | } | |
267 | ||
268 | //____________________________________________________________________ | |
269 | AliFMDBaseDigitizer::~AliFMDBaseDigitizer() | |
270 | { | |
271 | // Destructor | |
272 | } | |
273 | ||
274 | //____________________________________________________________________ | |
275 | Bool_t | |
276 | AliFMDBaseDigitizer::Init() | |
277 | { | |
278 | // Initialization | |
279 | AliFMDParameters::Instance()->Init(); | |
8b26caab | 280 | if (AliLog::GetDebugLevel("FMD","") >= 10) |
281 | AliFMDParameters::Instance()->Print("ALL"); | |
02a27b50 | 282 | return kTRUE; |
283 | } | |
42f1b2f5 | 284 | |
285 | //____________________________________________________________________ | |
286 | void | |
287 | AliFMDBaseDigitizer::Exec(Option_t* /*option*/) | |
288 | { | |
289 | AliFMDDebug(1, ("Executing digitizer")); | |
290 | AliFMD* fmd = 0; | |
291 | AliLoader* outFMD = 0; | |
292 | if (!SetupLoaders(fmd, outFMD)) return; | |
293 | if (!LoopOverInput(fmd)) return; | |
294 | ||
295 | // Digitize the event | |
296 | DigitizeHits(fmd); | |
297 | ||
298 | // Make the output | |
299 | AliFMDDebug(5, ("Calling output tree")); | |
300 | OutputTree(outFMD, fmd); | |
301 | } | |
302 | ||
303 | ||
304 | //____________________________________________________________________ | |
305 | Bool_t | |
306 | AliFMDBaseDigitizer::SetupLoaders(AliFMD*& fmd, AliLoader*& outFMD) | |
307 | { | |
308 | // Set-up input/output loaders. | |
309 | AliFMDDebug(5, ("Setting up run-loaders")); | |
310 | ||
311 | // Get the output manager and the FMD output manager | |
312 | TString outFolder(fManager->GetOutputFolderName()); | |
313 | AliRunLoader* out = AliRunLoader::GetRunLoader(outFolder.Data()); | |
314 | outFMD = out->GetLoader("FMDLoader"); | |
315 | if (!outFMD) { | |
316 | AliError("Cannot get the FMDLoader output folder"); | |
317 | return kFALSE; | |
318 | } | |
319 | ||
320 | // Get the input loader | |
321 | TString inFolder(fManager->GetInputFolderName(0)); | |
322 | fRunLoader = AliRunLoader::GetRunLoader(inFolder.Data()); | |
323 | if (!fRunLoader) { | |
324 | AliError("Can not find Run Loader for input stream 0"); | |
325 | return kFALSE; | |
326 | } | |
327 | ||
328 | // Get the AliRun object | |
329 | if (!fRunLoader->GetAliRun()) { | |
330 | AliWarning("Loading gAlice"); | |
331 | fRunLoader->LoadgAlice(); | |
332 | } | |
333 | ||
334 | // Get the AliRun object | |
335 | AliRun* run = fRunLoader->GetAliRun(); | |
336 | if (!run) { | |
337 | AliError("Can not get Run from Run Loader"); | |
338 | return kFALSE; | |
339 | } | |
340 | ||
341 | // Get the AliFMD object | |
342 | fmd = static_cast<AliFMD*>(run->GetDetector("FMD")); | |
343 | if (!fmd) { | |
344 | AliError("Can not get FMD from gAlice"); | |
345 | return kFALSE; | |
346 | } | |
347 | return kTRUE; | |
348 | } | |
349 | ||
350 | //____________________________________________________________________ | |
351 | Bool_t | |
352 | AliFMDBaseDigitizer::LoopOverInput(AliFMD* fmd) | |
353 | { | |
354 | if (!fManager) { | |
355 | AliError("No digitisation manager defined"); | |
356 | return kFALSE; | |
357 | } | |
358 | ||
359 | Int_t nFiles= fManager->GetNinputs(); | |
360 | AliFMDDebug(1, (" Digitizing event number %d, got %d inputs", | |
361 | fManager->GetOutputEventNr(), nFiles)); | |
362 | for (Int_t inputFile = 0; inputFile < nFiles; inputFile++) { | |
363 | AliFMDDebug(5, ("Now reading input # %d", inputFile)); | |
364 | // Get the current loader | |
365 | fRunLoader = | |
366 | AliRunLoader::GetRunLoader(fManager->GetInputFolderName(inputFile)); | |
367 | if (!fRunLoader) { | |
368 | Error("Exec", Form("no run loader for input file # %d", inputFile)); | |
369 | return kFALSE; | |
370 | } | |
371 | // Cache contriutions | |
372 | AliFMDDebug(5, ("Now summing the contributions from input # %d",inputFile)); | |
373 | SumContributions(fmd); | |
374 | } | |
375 | return kTRUE; | |
376 | } | |
377 | ||
02a27b50 | 378 | |
379 | //____________________________________________________________________ | |
380 | UShort_t | |
381 | AliFMDBaseDigitizer::MakePedestal(UShort_t, | |
382 | Char_t, | |
383 | UShort_t, | |
384 | UShort_t) const | |
385 | { | |
386 | // Make a pedestal | |
387 | return 0; | |
388 | } | |
389 | ||
390 | //____________________________________________________________________ | |
391 | void | |
392 | AliFMDBaseDigitizer::SumContributions(AliFMD* fmd) | |
393 | { | |
394 | // Sum energy deposited contributions from each hit in a cache | |
395 | // (fEdep). | |
396 | if (!fRunLoader) | |
397 | Fatal("SumContributions", "no run loader"); | |
398 | ||
399 | // Clear array of deposited energies | |
400 | fEdep.Reset(); | |
401 | ||
402 | // Get the FMD loader | |
403 | AliLoader* inFMD = fRunLoader->GetLoader("FMDLoader"); | |
404 | // And load the hits | |
42f1b2f5 | 405 | AliFMDDebug(5, ("Will read hits")); |
02a27b50 | 406 | inFMD->LoadHits("READ"); |
407 | ||
408 | // Get the tree of hits | |
42f1b2f5 | 409 | AliFMDDebug(5, ("Will get hit tree")); |
02a27b50 | 410 | TTree* hitsTree = inFMD->TreeH(); |
411 | if (!hitsTree) { | |
412 | // Try again | |
42f1b2f5 | 413 | AliFMDDebug(5, ("First attempt failed, try again")); |
02a27b50 | 414 | inFMD->LoadHits("READ"); |
415 | hitsTree = inFMD->TreeH(); | |
416 | } | |
417 | ||
418 | // Get the FMD branch | |
42f1b2f5 | 419 | AliFMDDebug(5, ("Will now get the branch")); |
02a27b50 | 420 | TBranch* hitsBranch = hitsTree->GetBranch("FMD"); |
421 | if (hitsBranch) fmd->SetHitsAddressBranch(hitsBranch); | |
422 | else AliFatal("Branch FMD hit not found"); | |
423 | ||
424 | // Get a list of hits from the FMD manager | |
42f1b2f5 | 425 | AliFMDDebug(5, ("Get array of FMD hits")); |
02a27b50 | 426 | TClonesArray *fmdHits = fmd->Hits(); |
427 | ||
428 | // Get number of entries in the tree | |
42f1b2f5 | 429 | AliFMDDebug(5, ("Get # of tracks")); |
02a27b50 | 430 | Int_t ntracks = Int_t(hitsTree->GetEntries()); |
42f1b2f5 | 431 | AliFMDDebug(5, ("We got %d tracks", ntracks)); |
02a27b50 | 432 | |
433 | AliFMDParameters* param = AliFMDParameters::Instance(); | |
434 | Int_t read = 0; | |
435 | // Loop over the tracks in the | |
436 | for (Int_t track = 0; track < ntracks; track++) { | |
437 | // Read in entry number `track' | |
438 | read += hitsBranch->GetEntry(track); | |
439 | ||
440 | // Get the number of hits | |
441 | Int_t nhits = fmdHits->GetEntries (); | |
442 | for (Int_t hit = 0; hit < nhits; hit++) { | |
443 | // Get the hit number `hit' | |
444 | AliFMDHit* fmdHit = | |
445 | static_cast<AliFMDHit*>(fmdHits->UncheckedAt(hit)); | |
446 | ||
447 | // Extract parameters | |
448 | UShort_t detector = fmdHit->Detector(); | |
449 | Char_t ring = fmdHit->Ring(); | |
450 | UShort_t sector = fmdHit->Sector(); | |
451 | UShort_t strip = fmdHit->Strip(); | |
452 | Float_t edep = fmdHit->Edep(); | |
42f1b2f5 | 453 | AliFMDDebug(10, ("Hit in FMD%d%c[%2d,%3d]=%f", |
f95a63c4 | 454 | detector, ring, sector, strip, edep)); |
42f1b2f5 | 455 | // Check if strip is `dead' |
02a27b50 | 456 | if (param->IsDead(detector, ring, sector, strip)) { |
f95a63c4 | 457 | AliFMDDebug(1, ("FMD%d%c[%2d,%3d] is marked as dead", |
02a27b50 | 458 | detector, ring, sector, strip)); |
459 | continue; | |
460 | } | |
42f1b2f5 | 461 | // UShort_t minstrip = param->GetMinStrip(detector, ring, sector, strip); |
462 | // UShort_t maxstrip = param->GetMaxStrip(detector, ring, sector, strip); | |
02a27b50 | 463 | // Check if strip is out-side read-out range |
15b17c89 | 464 | // if (strip < minstrip || strip > maxstrip) { |
f95a63c4 | 465 | // AliFMDDebug(5, ("FMD%d%c[%2d,%3d] is outside range [%3d,%3d]", |
15b17c89 | 466 | // detector,ring,sector,strip,minstrip,maxstrip)); |
467 | // continue; | |
468 | // } | |
02a27b50 | 469 | |
470 | // Give warning in case of double hit | |
471 | if (fEdep(detector, ring, sector, strip).fEdep != 0) | |
f95a63c4 | 472 | AliFMDDebug(5, ("Double hit in %d%c(%d,%d)", |
02a27b50 | 473 | detector, ring, sector, strip)); |
474 | ||
475 | // Sum energy deposition | |
476 | fEdep(detector, ring, sector, strip).fEdep += edep; | |
477 | fEdep(detector, ring, sector, strip).fN += 1; | |
478 | // Add this to the energy deposited for this strip | |
479 | } // hit loop | |
480 | } // track loop | |
42f1b2f5 | 481 | AliFMDDebug(5, ("Size of cache: %d bytes, read %d bytes", |
02a27b50 | 482 | sizeof(fEdep), read)); |
42f1b2f5 | 483 | inFMD->UnloadHits(); |
02a27b50 | 484 | } |
485 | ||
486 | //____________________________________________________________________ | |
487 | void | |
488 | AliFMDBaseDigitizer::DigitizeHits(AliFMD* fmd) const | |
489 | { | |
490 | // For the stored energy contributions in the cache (fEdep), convert | |
491 | // the energy signal to ADC counts, and store the created digit in | |
492 | // the digits array (AliFMD::fDigits) | |
493 | // | |
42f1b2f5 | 494 | AliFMDDebug(5, ("Will now digitize all the summed signals")); |
02a27b50 | 495 | AliFMDGeometry* geometry = AliFMDGeometry::Instance(); |
496 | ||
2aeec17d | 497 | TArrayI counts(4); |
02a27b50 | 498 | for (UShort_t detector=1; detector <= 3; detector++) { |
f95a63c4 | 499 | AliFMDDebug(5, ("Processing hits in FMD%d", detector)); |
02a27b50 | 500 | // Get pointer to subdetector |
501 | AliFMDDetector* det = geometry->GetDetector(detector); | |
502 | if (!det) continue; | |
503 | for (UShort_t ringi = 0; ringi <= 1; ringi++) { | |
504 | Char_t ring = ringi == 0 ? 'I' : 'O'; | |
f95a63c4 | 505 | AliFMDDebug(5, (" Processing hits in FMD%d%c", detector,ring)); |
02a27b50 | 506 | // Get pointer to Ring |
507 | AliFMDRing* r = det->GetRing(ring); | |
508 | if (!r) continue; | |
509 | ||
510 | // Get number of sectors | |
511 | UShort_t nSectors = UShort_t(360. / r->GetTheta()); | |
512 | // Loop over the number of sectors | |
513 | for (UShort_t sector = 0; sector < nSectors; sector++) { | |
f95a63c4 | 514 | AliFMDDebug(5, (" Processing hits in FMD%d%c[%2d]", |
515 | detector,ring,sector)); | |
02a27b50 | 516 | // Get number of strips |
517 | UShort_t nStrips = r->GetNStrips(); | |
518 | // Loop over the stips | |
519 | Float_t last = 0; | |
520 | for (UShort_t strip = 0; strip < nStrips; strip++) { | |
521 | // Reset the counter array to the invalid value -1 | |
522 | counts.Reset(-1); | |
523 | // Reset the last `ADC' value when we've get to the end of a | |
524 | // VA1_ALICE channel. | |
525 | if (strip % 128 == 0) last = 0; | |
526 | ||
527 | Float_t edep = fEdep(detector, ring, sector, strip).fEdep; | |
528 | ConvertToCount(edep, last, detector, ring, sector, strip, counts); | |
529 | last = edep; | |
8b26caab | 530 | |
531 | // The following line was introduced - wrongly - by Peter | |
532 | // Hristov. It _will_ break the digitisation and the | |
533 | // following reconstruction. The behviour of the | |
534 | // digitisation models exactly the front-end as it should | |
535 | // (no matter what memory concuption it may entail). The | |
536 | // check should be on zero suppression, since that's what | |
537 | // models the front-end - if zero suppression is turned on | |
538 | // in the front-end, then we can suppress empty digits - | |
539 | // otherwise we shoud never do that. Note, that the line | |
540 | // affects _both_ normal digitisation and digitisation for | |
541 | // summable digits, since the condition is on the energy | |
542 | // deposition and not on the actual number of counts. If | |
543 | // this line should go anywhere, it should be in the | |
544 | // possible overloaded AliFMDSDigitizer::AddDigit - not | |
545 | // here. | |
546 | // | |
547 | // if (edep<=0) continue; | |
02a27b50 | 548 | AddDigit(fmd, detector, ring, sector, strip, edep, |
549 | UShort_t(counts[0]), Short_t(counts[1]), | |
2aeec17d | 550 | Short_t(counts[2]), Short_t(counts[3])); |
f95a63c4 | 551 | AliFMDDebug(10, (" Adding digit in FMD%d%c[%2d,%3d]=%d", |
552 | detector,ring,sector,strip,counts[0])); | |
02a27b50 | 553 | #if 0 |
554 | // This checks if the digit created will give the `right' | |
555 | // number of particles when reconstructed, using a naiive | |
556 | // approach. It's here only as a quality check - nothing | |
557 | // else. | |
558 | CheckDigit(digit, fEdep(detector, ring, sector, strip).fN, | |
559 | counts); | |
560 | #endif | |
561 | } // Strip | |
562 | } // Sector | |
563 | } // Ring | |
564 | } // Detector | |
565 | } | |
566 | ||
567 | //____________________________________________________________________ | |
568 | void | |
569 | AliFMDBaseDigitizer::ConvertToCount(Float_t edep, | |
570 | Float_t last, | |
571 | UShort_t detector, | |
572 | Char_t ring, | |
573 | UShort_t sector, | |
574 | UShort_t strip, | |
575 | TArrayI& counts) const | |
576 | { | |
577 | // Convert the total energy deposited to a (set of) ADC count(s). | |
578 | // | |
579 | // This is done by | |
580 | // | |
581 | // Energy_Deposited ALTRO_Channel_Size | |
582 | // ADC = -------------------------- ------------------- + pedestal | |
583 | // Energy_Deposition_Of_1_MIP VA1_ALICE_MIP_Range | |
584 | // | |
585 | // Energy_Deposited fAltroChannelSize | |
586 | // = --------------------------------- ----------------- + pedestal | |
587 | // 1.664 * Si_Thickness * Si_Density fVA1MipRange | |
588 | // | |
589 | // | |
590 | // = Energy_Deposited * ConversionFactor + pedestal | |
591 | // | |
592 | // However, this is modified by the response function of the | |
593 | // VA1_ALICE pre-amp. chip in case we are doing oversampling of the | |
594 | // VA1_ALICE output. | |
595 | // | |
596 | // In that case, we get N=fSampleRate values of the ADC, and the | |
597 | // `EnergyDeposited' is a function of which sample where are | |
598 | // calculating the ADC for | |
599 | // | |
600 | // ADC_i = f(EnergyDeposited, i/N, Last) * ConversionFactor + pedestal | |
601 | // | |
602 | // where Last is the Energy deposited in the previous strip. | |
603 | // | |
604 | // Here, f is the shaping function of the VA1_ALICE. This is given | |
605 | // by | |
606 | // | |
607 | // | (E - l) * (1 - exp(-B * t) + l if E > l | |
608 | // f(E, t, l) = < | |
609 | // | (l - E) * exp(-B * t) + E otherwise | |
610 | // | |
611 | // | |
612 | // = E + (l - E) * ext(-B * t) | |
613 | // | |
614 | AliFMDParameters* param = AliFMDParameters::Instance(); | |
a9579262 | 615 | Float_t convF = 1./param->GetPulseGain(detector,ring,sector,strip); |
616 | Int_t ped = MakePedestal(detector,ring,sector,strip); | |
617 | Int_t maxAdc = param->GetAltroChannelSize()-1; | |
618 | if (maxAdc < 0) { | |
619 | AliWarning(Form("Maximum ADC is %d < 0, forcing it to 1023", maxAdc)); | |
620 | maxAdc = 1023; | |
621 | } | |
02a27b50 | 622 | UShort_t rate = param->GetSampleRate(detector,ring,sector,strip); |
2aeec17d | 623 | if (rate < 1 || rate > 4) rate = 1; |
02a27b50 | 624 | |
625 | // In case we don't oversample, just return the end value. | |
626 | if (rate == 1) { | |
a9579262 | 627 | Float_t a = edep * convF + ped; |
628 | if (a < 0) a = 0; | |
629 | counts[0] = UShort_t(TMath::Min(a, Float_t(maxAdc))); | |
42f1b2f5 | 630 | AliFMDDebug(10, ("FMD%d%c[%2d,%3d]: converting ELoss %f to " |
a9579262 | 631 | "ADC %4d (%f,%d)", |
632 | detector,ring,sector,strip,edep,counts[0],convF,ped)); | |
02a27b50 | 633 | return; |
634 | } | |
635 | ||
636 | // Create a pedestal | |
637 | Float_t b = fShapingTime; | |
638 | for (Ssiz_t i = 0; i < rate; i++) { | |
2aeec17d | 639 | Float_t t = Float_t(i) / rate + 1./rate; |
a9579262 | 640 | Float_t s = edep + (last - edep) * TMath::Exp(-b * t); |
641 | Float_t a = Int_t(s * convF + ped); | |
642 | if (a < 0) a = 0; | |
643 | counts[i] = UShort_t(TMath::Min(a, Float_t(maxAdc))); | |
02a27b50 | 644 | } |
645 | } | |
646 | ||
647 | ||
648 | ||
649 | //____________________________________________________________________ | |
650 | // | |
651 | // EOF | |
652 | // | |
653 | ||
654 | ||
655 | ||
656 |