[904] | 1 | <!-- ******************************************************** --> |
---|
| 2 | <!-- --> |
---|
| 3 | <!-- [History] --> |
---|
| 4 | <!-- Converted to DocBook: Katsuya Amako, Aug-2006 --> |
---|
| 5 | <!-- Changed by: Katsuya Amako, 21-Sep-1998 --> |
---|
| 6 | <!-- Proof read by: Joe Chuma, 30-Jun-1999 --> |
---|
| 7 | <!-- Changed by: Dennis Wright, 29-Nov-2001 --> |
---|
| 8 | <!-- Changed by: Makoto Asai, 30-Nov-2005 --> |
---|
| 9 | <!-- --> |
---|
| 10 | <!-- ******************************************************** --> |
---|
| 11 | |
---|
| 12 | <!-- ******************* Section (Level#1) ****************** --> |
---|
| 13 | <sect1 id="sect.Hits"> |
---|
| 14 | <title> |
---|
| 15 | Hits |
---|
| 16 | </title> |
---|
| 17 | |
---|
| 18 | |
---|
| 19 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 20 | <sect2 id="sect.Hits.Hit"> |
---|
| 21 | <title> |
---|
| 22 | Hit |
---|
| 23 | </title> |
---|
| 24 | |
---|
| 25 | <para> |
---|
| 26 | A hit is a snapshot of the physical interaction of a track in the |
---|
| 27 | sensitive region of a detector. In it you can store information |
---|
| 28 | associated with a <emphasis>G4Step</emphasis> object. This information can be |
---|
| 29 | |
---|
| 30 | <itemizedlist spacing="compact"> |
---|
| 31 | <listitem><para> |
---|
| 32 | the position and time of the step, |
---|
| 33 | </para></listitem> |
---|
| 34 | <listitem><para> |
---|
| 35 | the momentum and energy of the track, |
---|
| 36 | </para></listitem> |
---|
| 37 | <listitem><para> |
---|
| 38 | the energy deposition of the step, |
---|
| 39 | </para></listitem> |
---|
| 40 | <listitem><para> |
---|
| 41 | geometrical information, |
---|
| 42 | </para></listitem> |
---|
| 43 | </itemizedlist> |
---|
| 44 | |
---|
| 45 | or any combination of the above. |
---|
| 46 | </para> |
---|
| 47 | |
---|
| 48 | <!-- ******* Bridgehead ******* --> |
---|
| 49 | <bridgehead renderas='sect4'> |
---|
| 50 | G4VHit |
---|
| 51 | </bridgehead> |
---|
| 52 | |
---|
| 53 | <para> |
---|
| 54 | <emphasis>G4VHit</emphasis> is an abstract base class which represents a hit. |
---|
| 55 | You must inherit this base class and derive your own concrete hit |
---|
| 56 | class(es). The member data of your concrete hit class can be, and |
---|
| 57 | should be, your choice. |
---|
| 58 | </para> |
---|
| 59 | |
---|
| 60 | <para> |
---|
| 61 | <emphasis>G4VHit</emphasis> has two virtual methods, <literal>Draw()</literal> and |
---|
| 62 | <literal>Print()</literal>. To draw or print out your concrete hits, these |
---|
| 63 | methods should be implemented. How to define the drawing method is |
---|
| 64 | described in <xref linkend="sect.VisPlylMrkTxt" />. |
---|
| 65 | </para> |
---|
| 66 | |
---|
| 67 | <!-- ******* Bridgehead ******* --> |
---|
| 68 | <bridgehead renderas='sect4'> |
---|
| 69 | G4THitsCollection |
---|
| 70 | </bridgehead> |
---|
| 71 | |
---|
| 72 | <para> |
---|
| 73 | <emphasis>G4VHit</emphasis> is an abstract class from which you derive your |
---|
| 74 | own concrete classes. During the processing of a given event, |
---|
| 75 | represented by a <emphasis>G4Event</emphasis> object, many objects of the hit |
---|
| 76 | class will be produced, collected and associated with the event. |
---|
| 77 | Therefore, for each concrete hit class you must also prepare a |
---|
| 78 | concrete class derived from <emphasis>G4VHitsCollection</emphasis>, an abstract |
---|
| 79 | class which represents a vector collection of user defined |
---|
| 80 | hits. |
---|
| 81 | </para> |
---|
| 82 | |
---|
| 83 | <para> |
---|
| 84 | <emphasis>G4THitsCollection</emphasis> is a template class derived from |
---|
| 85 | <emphasis>G4VHitsCollection</emphasis>, and the concrete hit collection class of |
---|
| 86 | a particular <emphasis>G4VHit</emphasis> concrete class can be instantiated from |
---|
| 87 | this template class. Each object of a hit collection must have a |
---|
| 88 | unique name for each event. |
---|
| 89 | </para> |
---|
| 90 | |
---|
| 91 | <para> |
---|
| 92 | <emphasis>G4Event</emphasis> has a <emphasis>G4HCofThisEvent</emphasis> class |
---|
| 93 | object, that is a container class of collections of hits. Hit collections are |
---|
| 94 | stored by their pointers, whose type is that of the base class. |
---|
| 95 | </para> |
---|
| 96 | |
---|
| 97 | <!-- ******* Bridgehead ******* --> |
---|
| 98 | <bridgehead renderas='sect4'> |
---|
| 99 | An example of a concrete hit class |
---|
| 100 | </bridgehead> |
---|
| 101 | |
---|
| 102 | <para> |
---|
| 103 | <xref linkend="programlist_Hits_1" /> shows an example of a concrete hit class. |
---|
| 104 | |
---|
| 105 | <example id="programlist_Hits_1"> |
---|
| 106 | <title> |
---|
| 107 | An example of a concrete hit class. |
---|
| 108 | </title> |
---|
| 109 | |
---|
| 110 | <programlisting> |
---|
| 111 | #ifndef ExN04TrackerHit_h |
---|
| 112 | #define ExN04TrackerHit_h 1 |
---|
| 113 | |
---|
| 114 | #include "G4VHit.hh" |
---|
| 115 | #include "G4THitsCollection.hh" |
---|
| 116 | #include "G4Allocator.hh" |
---|
| 117 | #include "G4ThreeVector.hh" |
---|
| 118 | |
---|
| 119 | class ExN04TrackerHit : public G4VHit |
---|
| 120 | { |
---|
| 121 | public: |
---|
| 122 | |
---|
| 123 | ExN04TrackerHit(); |
---|
| 124 | ~ExN04TrackerHit(); |
---|
| 125 | ExN04TrackerHit(const ExN04TrackerHit &right); |
---|
| 126 | const ExN04TrackerHit& operator=(const ExN04TrackerHit &right); |
---|
| 127 | int operator==(const ExN04TrackerHit &right) const; |
---|
| 128 | |
---|
| 129 | inline void * operator new(size_t); |
---|
| 130 | inline void operator delete(void *aHit); |
---|
| 131 | |
---|
| 132 | void Draw() const; |
---|
| 133 | void Print() const; |
---|
| 134 | |
---|
| 135 | private: |
---|
| 136 | G4double edep; |
---|
| 137 | G4ThreeVector pos; |
---|
| 138 | |
---|
| 139 | public: |
---|
| 140 | inline void SetEdep(G4double de) |
---|
| 141 | { edep = de; } |
---|
| 142 | inline G4double GetEdep() const |
---|
| 143 | { return edep; } |
---|
| 144 | inline void SetPos(G4ThreeVector xyz) |
---|
| 145 | { pos = xyz; } |
---|
| 146 | inline G4ThreeVector GetPos() const |
---|
| 147 | { return pos; } |
---|
| 148 | |
---|
| 149 | }; |
---|
| 150 | |
---|
| 151 | typedef G4THitsCollection<ExN04TrackerHit> ExN04TrackerHitsCollection; |
---|
| 152 | |
---|
| 153 | extern G4Allocator<ExN04TrackerHit> ExN04TrackerHitAllocator; |
---|
| 154 | |
---|
| 155 | inline void* ExN04TrackerHit::operator new(size_t) |
---|
| 156 | { |
---|
| 157 | void *aHit; |
---|
| 158 | aHit = (void *) ExN04TrackerHitAllocator.MallocSingle(); |
---|
| 159 | return aHit; |
---|
| 160 | } |
---|
| 161 | |
---|
| 162 | inline void ExN04TrackerHit::operator delete(void *aHit) |
---|
| 163 | { |
---|
| 164 | ExN04TrackerHitAllocator.FreeSingle((ExN04TrackerHit*) aHit); |
---|
| 165 | } |
---|
| 166 | |
---|
| 167 | #endif |
---|
| 168 | </programlisting> |
---|
| 169 | </example> |
---|
| 170 | </para> |
---|
| 171 | |
---|
| 172 | <para> |
---|
| 173 | <emphasis>G4Allocator</emphasis> is a class for fast allocation of objects to |
---|
| 174 | the heap through the paging mechanism. For details of |
---|
| 175 | <emphasis>G4Allocator</emphasis>, refer to <xref linkend="sect.GeneManage" />. |
---|
| 176 | Use of <emphasis>G4Allocator</emphasis> |
---|
| 177 | is not mandatory, but it is recommended, especially for users who |
---|
| 178 | are not familiar with the C++ memory allocation mechanism or |
---|
| 179 | alternative tools of memory allocation. On the other hand, note |
---|
| 180 | that <emphasis>G4Allocator</emphasis> is to be used |
---|
| 181 | <emphasis role="bold">only</emphasis> for the concrete |
---|
| 182 | class that is <emphasis role="bold">not</emphasis> used as a base |
---|
| 183 | class of any other classes. |
---|
| 184 | For example, do <emphasis role="bold">not</emphasis> use the |
---|
| 185 | <emphasis>G4Trajectory</emphasis> class as a |
---|
| 186 | base class for a customized trajectory class, since |
---|
| 187 | <emphasis>G4Trajectory</emphasis> uses <emphasis>G4Allocator</emphasis>. |
---|
| 188 | </para> |
---|
| 189 | |
---|
| 190 | <!-- ******* Bridgehead ******* --> |
---|
| 191 | <bridgehead renderas='sect4'> |
---|
| 192 | G4THitsMap |
---|
| 193 | </bridgehead> |
---|
| 194 | |
---|
| 195 | <para> |
---|
| 196 | <emphasis>G4THitsMap</emphasis> is an alternative to |
---|
| 197 | <emphasis>G4THitsCollection</emphasis>. |
---|
| 198 | <emphasis>G4THitsMap</emphasis> does not demand <emphasis>G4VHit</emphasis>, |
---|
| 199 | but instead any variable which can be mapped with an integer key. Typically the key |
---|
| 200 | is a copy number of the volume, and the mapped value could for |
---|
| 201 | example be a double, such as the energy deposition in a volume. |
---|
| 202 | <emphasis>G4THitsMap</emphasis> is convenient for applications which do not need |
---|
| 203 | to output event-by-event data but instead just accumulate them. All |
---|
| 204 | the <emphasis>G4VPrimitiveScorer</emphasis> classes discussed in |
---|
| 205 | <xref linkend="sect.Hits.G4Multi" /> use <emphasis>G4THitsMap</emphasis>. |
---|
| 206 | </para> |
---|
| 207 | |
---|
| 208 | <para> |
---|
| 209 | <emphasis>G4THitsMap</emphasis> is derived from the |
---|
| 210 | <emphasis>G4VHitsCollection</emphasis> |
---|
| 211 | abstract base class and all objects of this class are also stored |
---|
| 212 | in <emphasis>G4HCofThisEvent</emphasis> at the end of an event. How to access a |
---|
| 213 | <emphasis>G4THitsMap</emphasis> object is discussed in the |
---|
| 214 | following section (<xref linkend="sect.Hits.G4Multi" />). |
---|
| 215 | </para> |
---|
| 216 | |
---|
| 217 | </sect2> |
---|
| 218 | |
---|
| 219 | |
---|
| 220 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 221 | <sect2 id="sect.Hits.SensDet"> |
---|
| 222 | <title> |
---|
| 223 | Sensitive detector |
---|
| 224 | </title> |
---|
| 225 | |
---|
| 226 | <!-- ******* Bridgehead ******* --> |
---|
| 227 | <bridgehead renderas='sect4'> |
---|
| 228 | G4VSensitiveDetector |
---|
| 229 | </bridgehead> |
---|
| 230 | |
---|
| 231 | <para> |
---|
| 232 | <emphasis>G4VSensitiveDetector</emphasis> is an abstract base class which |
---|
| 233 | represents a detector. The principal mandate of a sensitive |
---|
| 234 | detector is the construction of hit objects using information from |
---|
| 235 | steps along a particle track. The <literal>ProcessHits()</literal> method of |
---|
| 236 | <emphasis>G4VSensitiveDetector</emphasis> performs this task using |
---|
| 237 | <emphasis>G4Step</emphasis> |
---|
| 238 | objects as input. In the case of a "Readout" geometry (see |
---|
| 239 | <xref linkend="sect.Hits.ReadGeom" />), objects of the |
---|
| 240 | <emphasis>G4TouchableHistory</emphasis> class may be used as an optional input. |
---|
| 241 | </para> |
---|
| 242 | |
---|
| 243 | <para> |
---|
| 244 | Your concrete detector class should be instantiated with the |
---|
| 245 | unique name of your detector. The name can be associated with one |
---|
| 246 | or more global names with "/" as a delimiter for categorizing your |
---|
| 247 | detectors. For example |
---|
| 248 | |
---|
| 249 | <informalexample> |
---|
| 250 | <programlisting> |
---|
| 251 | myEMcal = new MyEMcal("/myDet/myCal/myEMcal"); |
---|
| 252 | </programlisting> |
---|
| 253 | </informalexample> |
---|
| 254 | |
---|
| 255 | where <literal>myEMcal</literal> is the name of your detector. The pointer to |
---|
| 256 | your sensitive detector must be set to one or more |
---|
| 257 | <emphasis>G4LogicalVolume</emphasis> objects to set the sensitivity of these |
---|
| 258 | volumes. The pointer should also be registered to |
---|
| 259 | <emphasis>G4SDManager</emphasis>, as described in |
---|
| 260 | <xref linkend="sect.Hits.G4SDMan" />. |
---|
| 261 | </para> |
---|
| 262 | |
---|
| 263 | <para> |
---|
| 264 | <emphasis>G4VSensitiveDetector</emphasis> has three major virtual methods. |
---|
| 265 | |
---|
| 266 | <variablelist><title></title> |
---|
| 267 | <varlistentry> |
---|
| 268 | <term> |
---|
| 269 | <literal>ProcessHits()</literal> |
---|
| 270 | </term> |
---|
| 271 | <listitem><para> |
---|
| 272 | This method is invoked by <emphasis>G4SteppingManager</emphasis> when a step |
---|
| 273 | is composed in the <emphasis>G4LogicalVolume</emphasis> which has the pointer |
---|
| 274 | to this sensitive detector. The first argument of this method is a |
---|
| 275 | <emphasis>G4Step</emphasis> object of the current step. The second argument is a |
---|
| 276 | <emphasis>G4TouchableHistory</emphasis> object for the ``Readout geometry'' |
---|
| 277 | described in the next section. The second argument is <literal>NULL</literal> |
---|
| 278 | if ``Readout geometry'' is not assigned to this sensitive detector. |
---|
| 279 | In this method, one or more <emphasis>G4VHit</emphasis> objects should be |
---|
| 280 | constructed if the current step is meaningful for your |
---|
| 281 | detector. |
---|
| 282 | </para></listitem> |
---|
| 283 | </varlistentry> |
---|
| 284 | <varlistentry> |
---|
| 285 | <term> |
---|
| 286 | <literal>Initialize()</literal> |
---|
| 287 | </term> |
---|
| 288 | <listitem><para> |
---|
| 289 | This method is invoked at the beginning of each event. The |
---|
| 290 | argument of this method is an object of the <emphasis>G4HCofThisEvent</emphasis> |
---|
| 291 | class. Hit collections, where hits produced in this particular |
---|
| 292 | event are stored, can be associated with the <emphasis>G4HCofThisEvent</emphasis> |
---|
| 293 | object in this method. The hit collections associated with the |
---|
| 294 | <emphasis>G4HCofThisEvent</emphasis> object during this method can be used for |
---|
| 295 | ``during the event processing'' digitization. |
---|
| 296 | </para></listitem> |
---|
| 297 | </varlistentry> |
---|
| 298 | <varlistentry> |
---|
| 299 | <term> |
---|
| 300 | <literal>EndOfEvent()</literal> |
---|
| 301 | </term> |
---|
| 302 | <listitem><para> |
---|
| 303 | This method is invoked at the end of each event. The argument |
---|
| 304 | of this method is the same object as the previous method. Hit |
---|
| 305 | collections occasionally created in your sensitive detector can be |
---|
| 306 | associated with the <emphasis>G4HCofThisEvent</emphasis> object. |
---|
| 307 | </para></listitem> |
---|
| 308 | </varlistentry> |
---|
| 309 | </variablelist> |
---|
| 310 | </para> |
---|
| 311 | |
---|
| 312 | </sect2> |
---|
| 313 | |
---|
| 314 | |
---|
| 315 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 316 | <sect2 id="sect.Hits.ReadGeom"> |
---|
| 317 | <title> |
---|
| 318 | Readout geometry |
---|
| 319 | </title> |
---|
| 320 | |
---|
| 321 | <para> |
---|
| 322 | This section describes how a ``Readout geometry'' can be defined. A |
---|
| 323 | Readout geometry is a virtual, parallel geometry for obtaining the |
---|
| 324 | channel number. |
---|
| 325 | </para> |
---|
| 326 | |
---|
| 327 | <para> |
---|
| 328 | As an example, the accordion calorimeter of <emphasis role="bold">ATLAS</emphasis> |
---|
| 329 | has a complicated tracking geometry, however the readout can be done by |
---|
| 330 | simple cylindrical sectors divided by theta, phi, and depth. Tracks |
---|
| 331 | will be traced in the tracking geometry, the ``real'' one, and the |
---|
| 332 | sensitive detector will have its own readout geometry Geant4 will |
---|
| 333 | message to find to which ``readout'' cell the current hit |
---|
| 334 | belongs. |
---|
| 335 | |
---|
| 336 | <figure id="fig.Hits_1"> |
---|
| 337 | <title> |
---|
| 338 | Association of tracking and readout geometry. |
---|
| 339 | </title> |
---|
| 340 | <mediaobject> |
---|
| 341 | <imageobject role="fo"> |
---|
[1211] | 342 | <imagedata fileref="./AllResources/Detector/hit.src/RO.jpg" |
---|
[904] | 343 | format="JPG" contentwidth="10.0cm" align="center" /> |
---|
| 344 | </imageobject> |
---|
| 345 | <imageobject role="html"> |
---|
[1211] | 346 | <imagedata fileref="./AllResources/Detector/hit.src/RO.jpg" |
---|
[904] | 347 | format="JPG" align="center" /> |
---|
| 348 | </imageobject> |
---|
| 349 | </mediaobject> |
---|
| 350 | </figure> |
---|
| 351 | </para> |
---|
| 352 | |
---|
| 353 | <para> |
---|
| 354 | <xref linkend="fig.Hits_1" /> shows how this association is done in Geant4. |
---|
| 355 | The first step is to associate a sensitive detector to a volume of the |
---|
| 356 | tracking geometry, in the usual way (see |
---|
| 357 | <xref linkend="sect.Hits.SensDet" />). The next step is to associate your |
---|
| 358 | <emphasis>G4VReadoutGeometry</emphasis> object to the sensitive detector. |
---|
| 359 | </para> |
---|
| 360 | |
---|
| 361 | <para> |
---|
| 362 | At tracking time, the base class <emphasis>G4VReadoutGeometry</emphasis> will |
---|
| 363 | provide to your sensitive detector code the |
---|
| 364 | <emphasis>G4TouchableHistory</emphasis> in the Readout geometry at the beginning |
---|
| 365 | of the step position (position of <emphasis>PreStepPoint</emphasis> of |
---|
| 366 | <emphasis>G4Step</emphasis>) and at this position only. |
---|
| 367 | </para> |
---|
| 368 | |
---|
| 369 | <para> |
---|
| 370 | This <emphasis>G4TouchableHistory</emphasis> is given to your sensitive |
---|
| 371 | detector code through the <emphasis>G4VSensitiveDetector</emphasis> virtual |
---|
| 372 | method: |
---|
| 373 | |
---|
| 374 | <informalexample> |
---|
| 375 | <programlisting> |
---|
| 376 | G4bool processHits(G4Step* aStep, G4TouchableHistory* ROhist); |
---|
| 377 | </programlisting> |
---|
| 378 | </informalexample> |
---|
| 379 | |
---|
| 380 | by the <literal>ROhist</literal> argument. |
---|
| 381 | </para> |
---|
| 382 | |
---|
| 383 | <para> |
---|
| 384 | Thus, you will be able to use information from both the |
---|
| 385 | <emphasis>G4Step</emphasis> and the <emphasis>G4TouchableHistory</emphasis> |
---|
| 386 | coming from your |
---|
| 387 | Readout geometry. Note that since the association is done through a |
---|
| 388 | sensitive detector object, it is perfectly possible to have several |
---|
| 389 | Readout geometries in parallel. |
---|
| 390 | </para> |
---|
| 391 | |
---|
| 392 | |
---|
| 393 | <!-- ******* Bridgehead ******* --> |
---|
| 394 | <bridgehead renderas='sect4'> |
---|
| 395 | Definition of a virtual geometry setup |
---|
| 396 | </bridgehead> |
---|
| 397 | |
---|
| 398 | <para> |
---|
| 399 | The base class for the implementation of a Readout geometry is |
---|
| 400 | <emphasis>G4VReadoutGeometry</emphasis>. This class has a single pure virtual |
---|
| 401 | protected method: |
---|
| 402 | |
---|
| 403 | <informalexample> |
---|
| 404 | <programlisting> |
---|
| 405 | virtual G4VPhysicalVolume* build() = 0; |
---|
| 406 | </programlisting> |
---|
| 407 | </informalexample> |
---|
| 408 | |
---|
| 409 | which you must override in your concrete class. The |
---|
| 410 | <emphasis>G4VPhysicalVolume</emphasis> pointer you will have to return is of the |
---|
| 411 | physical world of the Readout geometry. |
---|
| 412 | </para> |
---|
| 413 | |
---|
| 414 | <para> |
---|
| 415 | The step by step procedure for constructing a Readout geometry is: |
---|
| 416 | |
---|
| 417 | <itemizedlist spacing="compact"> |
---|
| 418 | <listitem><para> |
---|
| 419 | inherit from <emphasis>G4VReadoutGeometry</emphasis> to define a |
---|
| 420 | <emphasis>MyROGeom</emphasis> class; |
---|
| 421 | </para></listitem> |
---|
| 422 | <listitem><para> |
---|
| 423 | implement the Readout geometry in the <literal>build()</literal> method, |
---|
| 424 | returning the physical world of this geometry. |
---|
| 425 | <para> |
---|
| 426 | The world is specified in the same way as for the detector |
---|
| 427 | construction: a physical volume with no mother. The axis system of |
---|
| 428 | this world is the same as the one of the world for tracking. |
---|
| 429 | </para> |
---|
| 430 | <para> |
---|
| 431 | In this geometry you need to declare the sensitive parts in the |
---|
| 432 | same way as in the tracking geometry: by setting a |
---|
| 433 | non-<literal>NULL</literal> <emphasis>G4VSensitiveDetector</emphasis> |
---|
| 434 | pointer in, say, the |
---|
| 435 | relevant <emphasis>G4LogicalVolume</emphasis> objects. This sensitive class needs |
---|
| 436 | to be there, but will not be used. |
---|
| 437 | </para> |
---|
| 438 | <para> |
---|
| 439 | You will also need to assign well defined materials to the |
---|
| 440 | volumes you place in this geometry, but these materials are |
---|
| 441 | irrelevant since they will not be seen by the tracking. It is |
---|
| 442 | foreseen to allow the setting of a <literal>NULL</literal> pointer in this |
---|
| 443 | case of the parallel geometry. |
---|
| 444 | </para> |
---|
| 445 | </para></listitem> |
---|
| 446 | <listitem><para> |
---|
| 447 | in the <literal>construct()</literal> method of your concrete |
---|
| 448 | <emphasis>G4VUserDetectorConstruction</emphasis> class: |
---|
| 449 | <para> |
---|
| 450 | <itemizedlist spacing="compact"> |
---|
| 451 | <listitem><para> |
---|
| 452 | instantiate your Readout geometry: |
---|
| 453 | <informalexample> |
---|
| 454 | <programlisting> |
---|
| 455 | MyROGeom* ROgeom = new MyROGeom("ROName"); |
---|
| 456 | </programlisting> |
---|
| 457 | </informalexample> |
---|
| 458 | </para></listitem> |
---|
| 459 | <listitem><para> |
---|
| 460 | build it: |
---|
| 461 | <informalexample> |
---|
| 462 | <programlisting> |
---|
| 463 | ROgeom->buildROGeometry(); |
---|
| 464 | </programlisting> |
---|
| 465 | </informalexample> |
---|
| 466 | That will invoke your <literal>build()</literal> method. |
---|
| 467 | </para></listitem> |
---|
| 468 | <listitem><para> |
---|
| 469 | Instantiate the sensitive detector which will receive the |
---|
| 470 | <literal>ROGeom</literal> pointer, <literal>MySensitive</literal>, |
---|
| 471 | and add this sensitive to the <emphasis>G4SDManager</emphasis>. |
---|
| 472 | Associate this sensitive to |
---|
| 473 | the volume(s) of the tracking geometry as usual. |
---|
| 474 | </para></listitem> |
---|
| 475 | <listitem><para> |
---|
| 476 | Associate the sensitive to the Readout geometry: |
---|
| 477 | <informalexample> |
---|
| 478 | <programlisting> |
---|
| 479 | MySensitive->SetROgeometry(ROgeom); |
---|
| 480 | </programlisting> |
---|
| 481 | </informalexample> |
---|
| 482 | </para></listitem> |
---|
| 483 | </itemizedlist> |
---|
| 484 | </para> |
---|
| 485 | </para></listitem> |
---|
| 486 | </itemizedlist> |
---|
| 487 | </para> |
---|
| 488 | |
---|
| 489 | </sect2> |
---|
| 490 | |
---|
| 491 | |
---|
| 492 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 493 | <sect2 id="sect.Hits.G4SDMan"> |
---|
| 494 | <title> |
---|
| 495 | G4SDManager |
---|
| 496 | </title> |
---|
| 497 | |
---|
| 498 | <para> |
---|
| 499 | <emphasis>G4SDManager</emphasis> is the singleton manager class for sensitive |
---|
| 500 | detectors. |
---|
| 501 | </para> |
---|
| 502 | |
---|
| 503 | <!-- ******* Bridgehead ******* --> |
---|
| 504 | <bridgehead renderas='sect4'> |
---|
| 505 | Activation/inactivation of sensitive detectors |
---|
| 506 | </bridgehead> |
---|
| 507 | |
---|
| 508 | <para> |
---|
| 509 | The user interface commands <literal>activate</literal> and |
---|
| 510 | <literal>inactivate</literal> are available to control your sensitive |
---|
| 511 | detectors. For example: |
---|
| 512 | |
---|
| 513 | <informalexample> |
---|
| 514 | <programlisting> |
---|
| 515 | /hits/activate detector_name |
---|
| 516 | /hits/inactivate detector_name |
---|
| 517 | </programlisting> |
---|
| 518 | </informalexample> |
---|
| 519 | |
---|
| 520 | where <literal>detector_name</literal> can be the detector name or the |
---|
| 521 | category name. |
---|
| 522 | </para> |
---|
| 523 | |
---|
| 524 | <para> |
---|
| 525 | For example, if your EM calorimeter is named |
---|
| 526 | |
---|
| 527 | <informalexample> |
---|
| 528 | <programlisting> |
---|
| 529 | /myDet/myCal/myEMcal |
---|
| 530 | /hits/inactivate myCal |
---|
| 531 | </programlisting> |
---|
| 532 | </informalexample> |
---|
| 533 | |
---|
| 534 | will inactivate all detectors belonging to the <literal>myCal</literal> |
---|
| 535 | category. |
---|
| 536 | </para> |
---|
| 537 | |
---|
| 538 | <!-- ******* Bridgehead ******* --> |
---|
| 539 | <bridgehead renderas='sect4'> |
---|
| 540 | Access to the hit collections |
---|
| 541 | </bridgehead> |
---|
| 542 | |
---|
| 543 | |
---|
| 544 | <para>Hit collections are accessed for various cases. |
---|
| 545 | |
---|
| 546 | <itemizedlist spacing="compact"> |
---|
| 547 | <listitem><para> |
---|
| 548 | Digitization |
---|
| 549 | </para></listitem> |
---|
| 550 | <listitem><para> |
---|
| 551 | Event filtering in <emphasis>G4VUserStackingAction</emphasis> |
---|
| 552 | </para></listitem> |
---|
| 553 | <listitem><para> |
---|
| 554 | ``End of event'' simple analysis |
---|
| 555 | </para></listitem> |
---|
| 556 | <listitem><para> |
---|
| 557 | Drawing / printing hits |
---|
| 558 | </para></listitem> |
---|
| 559 | </itemizedlist> |
---|
| 560 | </para> |
---|
| 561 | |
---|
| 562 | <para> |
---|
| 563 | The following is an example of how to access the hit collection |
---|
| 564 | of a particular concrete type: |
---|
| 565 | |
---|
| 566 | <informalexample> |
---|
| 567 | <programlisting> |
---|
| 568 | G4SDManager* fSDM = G4SDManager::GetSDMpointer(); |
---|
| 569 | G4RunManager* fRM = G4RunManager::GetRunManager(); |
---|
| 570 | G4int collectionID = fSDM->GetCollectionID("collection_name"); |
---|
| 571 | const G4Event* currentEvent = fRM->GetCurrentEvent(); |
---|
| 572 | G4HCofThisEvent* HCofEvent = currentEvent->GetHCofThisEvent(); |
---|
| 573 | <emphasis>MyHitsCollection</emphasis>* myCollection = (<emphasis>MyHitsCollection</emphasis>*)(HC0fEvent->GetHC(collectionID)); |
---|
| 574 | </programlisting> |
---|
| 575 | </informalexample> |
---|
| 576 | </para> |
---|
| 577 | |
---|
| 578 | </sect2> |
---|
| 579 | |
---|
| 580 | |
---|
| 581 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 582 | <sect2 id="sect.Hits.G4Multi"> |
---|
| 583 | <title> |
---|
| 584 | <emphasis>G4MultiFunctionalDetector</emphasis> and |
---|
| 585 | <emphasis>G4VPrimitiveScorer</emphasis> |
---|
| 586 | </title> |
---|
| 587 | |
---|
| 588 | <para> |
---|
| 589 | <emphasis>G4MultiFunctionalDetector</emphasis> is a concrete class derived from |
---|
| 590 | <emphasis>G4VSensitiveDetector</emphasis>. Instead of implementing a |
---|
| 591 | user-specific detector class, <emphasis>G4MultiFunctionalDetector</emphasis> |
---|
| 592 | allows the user to register <emphasis>G4VPrimitiveScorer</emphasis> classes to |
---|
| 593 | build up the sensitivity. <emphasis>G4MultiFunctionalDetector</emphasis> should |
---|
| 594 | be instantiated in the users detector construction with its unique |
---|
| 595 | name and should be assigned to one or more <emphasis>G4LogicalVolume</emphasis>s. |
---|
| 596 | </para> |
---|
| 597 | |
---|
| 598 | <para> |
---|
| 599 | <emphasis>G4VPrimitiveScorer</emphasis> is an abstract base class representing |
---|
| 600 | a class to be registered to <emphasis>G4MultiFunctionalDetector</emphasis> that |
---|
| 601 | creates a <emphasis>G4THitsMap</emphasis> object of one physics quantity for an |
---|
| 602 | event. Geant4 provides many concrete primitive scorer classes |
---|
| 603 | listed in <xref linkend="sect.Hits.G4VPrim" />, and the user can |
---|
| 604 | also implement his/her own primitive scorers. Each primitive scorer |
---|
| 605 | object must be instantiated with a name that must be unique among |
---|
| 606 | primitive scorers registered in a <emphasis>G4MultiFunctionalDetector</emphasis>. |
---|
| 607 | Please note that a primitive scorer object must <emphasis role="bold">not</emphasis> be |
---|
| 608 | shared by more than one <emphasis>G4MultiFunctionalDetector</emphasis> |
---|
| 609 | object. |
---|
| 610 | </para> |
---|
| 611 | |
---|
| 612 | <para>As mentioned in <xref linkend="sect.Hits.Hit" />, |
---|
| 613 | each <emphasis>G4VPrimitiveScorer</emphasis> generates one |
---|
| 614 | <emphasis>G4THitsMap</emphasis> object |
---|
| 615 | per event. The name of the map object is the same as the name of |
---|
| 616 | the primitive scorer. Each of the concrete primitive scorers listed |
---|
| 617 | in <xref linkend="sect.Hits.G4VPrim" /> generates a |
---|
| 618 | <emphasis>G4THitsMap<G4double></emphasis> that maps a |
---|
| 619 | <emphasis>G4double</emphasis> value |
---|
| 620 | to its key integer number. By default, the key is taken as the copy |
---|
| 621 | number of the <emphasis>G4LogicalVolume</emphasis> to which |
---|
| 622 | <emphasis>G4MultiFunctionalDetector</emphasis> is assigned. In case the logical |
---|
| 623 | volume is uniquely placed in its mother volume and the mother is |
---|
| 624 | replicated, the copy number of its mother volume can be taken by |
---|
| 625 | setting the second argument of the <emphasis>G4VPrimitiveScorer</emphasis> |
---|
| 626 | constructor, "<emphasis>depth</emphasis>" to 1, i.e. one level up. Furthermore, |
---|
| 627 | in case the key must consider more than one copy number of a |
---|
| 628 | different geometry hierarchy, the user can derive his/her own |
---|
| 629 | primitive scorer from the provided concrete class and implement the |
---|
| 630 | <emphasis>GetIndex(G4Step*)</emphasis> virtual method to return the unique |
---|
| 631 | key. |
---|
| 632 | </para> |
---|
| 633 | |
---|
| 634 | <para> |
---|
| 635 | <xref linkend="programlist_Hits_2" /> shows an example of primitive sensitivity |
---|
| 636 | class definitions. |
---|
| 637 | |
---|
| 638 | <example id="programlist_Hits_2"> |
---|
| 639 | <title> |
---|
| 640 | An example of defining primitive sensitivity classes taken from |
---|
| 641 | <emphasis>ExN07DetectorConstruction</emphasis>. |
---|
| 642 | </title> |
---|
| 643 | <programlisting> |
---|
| 644 | void ExN07DetectorConstruction::SetupDetectors() |
---|
| 645 | { |
---|
| 646 | G4String filterName, particleName; |
---|
| 647 | |
---|
| 648 | G4SDParticleFilter* gammaFilter = |
---|
| 649 | new G4SDParticleFilter(filterName="gammaFilter",particleName="gamma"); |
---|
| 650 | G4SDParticleFilter* electronFilter = |
---|
| 651 | new G4SDParticleFilter(filterName="electronFilter",particleName="e-"); |
---|
| 652 | G4SDParticleFilter* positronFilter = |
---|
| 653 | new G4SDParticleFilter(filterName="positronFilter",particleName="e+"); |
---|
| 654 | G4SDParticleFilter* epFilter = new G4SDParticleFilter(filterName="epFilter"); |
---|
| 655 | epFilter->add(particleName="e-"); |
---|
| 656 | epFilter->add(particleName="e+"); |
---|
| 657 | |
---|
| 658 | |
---|
| 659 | for(G4int i=0;i<3;i++) |
---|
| 660 | { |
---|
| 661 | for(G4int j=0;j<2;j++) |
---|
| 662 | { |
---|
| 663 | // Loop counter j = 0 : absorber |
---|
| 664 | // = 1 : gap |
---|
| 665 | G4String detName = calName[i]; |
---|
| 666 | if(j==0) |
---|
| 667 | { detName += "_abs"; } |
---|
| 668 | else |
---|
| 669 | { detName += "_gap"; } |
---|
| 670 | G4MultiFunctionalDetector* det = new G4MultiFunctionalDetector(detName); |
---|
| 671 | |
---|
| 672 | // The second argument in each primitive means the "level" of geometrical hierarchy, |
---|
| 673 | // the copy number of that level is used as the key of the G4THitsMap. |
---|
| 674 | // For absorber (j = 0), the copy number of its own physical volume is used. |
---|
| 675 | // For gap (j = 1), the copy number of its mother physical volume is used, since there |
---|
| 676 | // is only one physical volume of gap is placed with respect to its mother. |
---|
| 677 | G4VPrimitiveScorer* primitive; |
---|
| 678 | primitive = new G4PSEnergyDeposit("eDep",j); |
---|
| 679 | det->RegisterPrimitive(primitive); |
---|
| 680 | primitive = new G4PSNofSecondary("nGamma",j); |
---|
| 681 | primitive->SetFilter(gammaFilter); |
---|
| 682 | det->RegisterPrimitive(primitive); |
---|
| 683 | primitive = new G4PSNofSecondary("nElectron",j); |
---|
| 684 | primitive->SetFilter(electronFilter); |
---|
| 685 | det->RegisterPrimitive(primitive); |
---|
| 686 | primitive = new G4PSNofSecondary("nPositron",j); |
---|
| 687 | primitive->SetFilter(positronFilter); |
---|
| 688 | det->RegisterPrimitive(primitive); |
---|
| 689 | primitive = new G4PSMinKinEAtGeneration("minEkinGamma",j); |
---|
| 690 | primitive->SetFilter(gammaFilter); |
---|
| 691 | det->RegisterPrimitive(primitive); |
---|
| 692 | primitive = new G4PSMinKinEAtGeneration("minEkinElectron",j); |
---|
| 693 | primitive->SetFilter(electronFilter); |
---|
| 694 | det->RegisterPrimitive(primitive); |
---|
| 695 | primitive = new G4PSMinKinEAtGeneration("minEkinPositron",j); |
---|
| 696 | primitive->SetFilter(positronFilter); |
---|
| 697 | det->RegisterPrimitive(primitive); |
---|
| 698 | primitive = new G4PSTrackLength("trackLength",j); |
---|
| 699 | primitive->SetFilter(epFilter); |
---|
| 700 | det->RegisterPrimitive(primitive); |
---|
| 701 | primitive = new G4PSNofStep("nStep",j); |
---|
| 702 | primitive->SetFilter(epFilter); |
---|
| 703 | det->RegisterPrimitive(primitive); |
---|
| 704 | |
---|
| 705 | G4SDManager::GetSDMpointer()->AddNewDetector(det); |
---|
| 706 | if(j==0) |
---|
| 707 | { layerLogical[i]->SetSensitiveDetector(det); } |
---|
| 708 | else |
---|
| 709 | { gapLogical[i]->SetSensitiveDetector(det); } |
---|
| 710 | } |
---|
| 711 | } |
---|
| 712 | } |
---|
| 713 | </programlisting> |
---|
| 714 | </example> |
---|
| 715 | </para> |
---|
| 716 | |
---|
| 717 | <para> |
---|
| 718 | Each <emphasis>G4THitsMap</emphasis> object can be accessed from |
---|
| 719 | <emphasis>G4HCofThisEvent</emphasis> with a unique collection ID number. This ID |
---|
| 720 | number can be obtained from <emphasis>G4SDManager::GetCollectionID()</emphasis> |
---|
| 721 | with a name of <emphasis>G4MultiFunctionalDetector</emphasis> and |
---|
| 722 | <emphasis>G4VPrimitiveScorer</emphasis> connected with a slush ("/"). |
---|
| 723 | <emphasis>G4THitsMap</emphasis> has a [] operator taking the key value as an |
---|
| 724 | argument and returning <emphasis role="bold">the pointer</emphasis> of the value. |
---|
| 725 | Please note that the [] operator returns |
---|
| 726 | <emphasis role="bold">the pointer</emphasis> of the value. If |
---|
| 727 | you get zero from the [] operator, it does <emphasis role="bold">not</emphasis> mean the |
---|
| 728 | value is zero, but that the provided key does not exist. The value |
---|
| 729 | itself is accessible with an astarisk ("*"). It is advised to check |
---|
| 730 | the validity of the returned pointer before accessing the value. |
---|
| 731 | <emphasis>G4THitsMap</emphasis> also has a += operator in order to accumulate |
---|
| 732 | event data into run data. <xref linkend="programlist_Hits_3" /> shows the use of |
---|
| 733 | <emphasis>G4THitsMap</emphasis>. |
---|
| 734 | |
---|
| 735 | <example id="programlist_Hits_3"> |
---|
| 736 | <title> |
---|
| 737 | An example of accessing to <emphasis>G4THitsMap</emphasis> objects. |
---|
| 738 | </title> |
---|
| 739 | |
---|
| 740 | <programlisting> |
---|
| 741 | #include "ExN07Run.hh" |
---|
| 742 | #include "G4Event.hh" |
---|
| 743 | #include "G4HCofThisEvent.hh" |
---|
| 744 | #include "G4SDManager.hh" |
---|
| 745 | |
---|
| 746 | ExN07Run::ExN07Run() |
---|
| 747 | { |
---|
| 748 | G4String detName[6] = {"Calor-A_abs","Calor-A_gap","Calor-B_abs","Calor-B_gap", |
---|
| 749 | "Calor-C_abs","Calor-C_gap"}; |
---|
| 750 | G4String primNameSum[6] = {"eDep","nGamma","nElectron","nPositron","trackLength","nStep"}; |
---|
| 751 | G4String primNameMin[3] = {"minEkinGamma","minEkinElectron","minEkinPositron"}; |
---|
| 752 | |
---|
| 753 | G4SDManager* SDMan = G4SDManager::GetSDMpointer(); |
---|
| 754 | G4String fullName; |
---|
| 755 | for(size_t i=0;i<6;i++) |
---|
| 756 | { |
---|
| 757 | for(size_t j=0;j<6;j++) |
---|
| 758 | { |
---|
| 759 | fullName = detName[i]+"/"+primNameSum[j]; |
---|
| 760 | colIDSum[i][j] = SDMan->GetCollectionID(fullName); |
---|
| 761 | } |
---|
| 762 | for(size_t k=0;k<3;k++) |
---|
| 763 | { |
---|
| 764 | fullName = detName[i]+"/"+primNameMin[k]; |
---|
| 765 | colIDMin[i][k] = SDMan->GetCollectionID(fullName); |
---|
| 766 | } |
---|
| 767 | } |
---|
| 768 | } |
---|
| 769 | |
---|
| 770 | |
---|
| 771 | void ExN07Run::RecordEvent(const G4Event* evt) |
---|
| 772 | { |
---|
| 773 | G4HCofThisEvent* HCE = evt->GetHCofThisEvent(); |
---|
| 774 | if(!HCE) return; |
---|
| 775 | numberOfEvent++; |
---|
| 776 | for(size_t i=0;i<6;i++) |
---|
| 777 | { |
---|
| 778 | for(size_t j=0;j<6;j++) |
---|
| 779 | { |
---|
| 780 | G4THitsMap<G4double>* evtMap = (G4THitsMap<G4double>*)(HCE->GetHC(colIDSum[i][j])); |
---|
| 781 | mapSum[i][j] += *evtMap; |
---|
| 782 | } |
---|
| 783 | for(size_t k=0;k<3;k++) |
---|
| 784 | { |
---|
| 785 | G4THitsMap<G4double>* evtMap = (G4THitsMap<G4double>*)(HCE->GetHC(colIDMin[i][k])); |
---|
| 786 | std::map<G4int,G4double*>::iterator itr = evtMap->GetMap()->begin(); |
---|
| 787 | for(; itr != evtMap->GetMap()->end(); itr++) |
---|
| 788 | { |
---|
| 789 | G4int key = (itr->first); |
---|
| 790 | G4double val = *(itr->second); |
---|
| 791 | G4double* mapP = mapMin[i][k][key]; |
---|
| 792 | if( mapP && (val>*mapP) ) continue; |
---|
| 793 | mapMin[i][k].set(key,val); |
---|
| 794 | } |
---|
| 795 | } |
---|
| 796 | } |
---|
| 797 | } |
---|
| 798 | </programlisting> |
---|
| 799 | </example> |
---|
| 800 | </para> |
---|
| 801 | |
---|
| 802 | </sect2> |
---|
| 803 | |
---|
| 804 | |
---|
| 805 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 806 | <sect2 id="sect.Hits.G4VPrim"> |
---|
| 807 | <title> |
---|
| 808 | Concrete classes of <emphasis>G4VPrimitiveScorer</emphasis> |
---|
| 809 | </title> |
---|
| 810 | |
---|
| 811 | <para> |
---|
| 812 | With Geant4 version 8.0, several concrete primitive scorer classes |
---|
| 813 | are provided, all of which are derived from the |
---|
| 814 | <emphasis>G4VPrimitiveScorer</emphasis> abstract base class and which are to be |
---|
| 815 | registered to <emphasis>G4MultiFunctionalDetector</emphasis>. Each of them |
---|
| 816 | contains one <emphasis>G4THitsMap</emphasis> object and scores a simple double |
---|
| 817 | value for each key. |
---|
| 818 | </para> |
---|
| 819 | |
---|
| 820 | <!-- ******* Bridgehead ******* --> |
---|
| 821 | <bridgehead renderas='sect4'> |
---|
| 822 | Track length scorers |
---|
| 823 | </bridgehead> |
---|
| 824 | |
---|
| 825 | <para> |
---|
| 826 | <variablelist><title></title> |
---|
| 827 | <varlistentry> |
---|
| 828 | <term> |
---|
| 829 | G4PSTrackLength |
---|
| 830 | </term> |
---|
| 831 | <listitem><para> |
---|
| 832 | The track length is defined as the sum of step lengths of the |
---|
| 833 | particles inside the cell. Bt default, the track weight is not |
---|
| 834 | taken into account, but could be used as a multiplier of each step |
---|
| 835 | length if the <emphasis>Weighted()</emphasis> method of this class object is |
---|
| 836 | invoked. |
---|
| 837 | </para></listitem> |
---|
| 838 | </varlistentry> |
---|
| 839 | <varlistentry> |
---|
| 840 | <term> |
---|
| 841 | G4PSPassageTrackLength |
---|
| 842 | </term> |
---|
| 843 | <listitem><para> |
---|
| 844 | The passage track length is the same as the track length in |
---|
| 845 | <emphasis>G4PSTrackLength</emphasis>, except that only tracks which pass |
---|
| 846 | through the volume are taken into account. It means newly-generated or |
---|
| 847 | stopped tracks inside the cell are excluded from the calculation. |
---|
| 848 | By default, the track weight is not taken into account, but could |
---|
| 849 | be used as a multiplier of each step length if the |
---|
| 850 | <emphasis>Weighted()</emphasis> method of this class object is invoked. |
---|
| 851 | </para></listitem> |
---|
| 852 | </varlistentry> |
---|
| 853 | </variablelist> |
---|
| 854 | </para> |
---|
| 855 | |
---|
| 856 | |
---|
| 857 | <!-- ******* Bridgehead ******* --> |
---|
| 858 | <bridgehead renderas='sect4'> |
---|
| 859 | <emphasis role="bold">Deposited energy scorers</emphasis> |
---|
| 860 | </bridgehead> |
---|
| 861 | |
---|
| 862 | <para> |
---|
| 863 | <variablelist><title></title> |
---|
| 864 | <varlistentry> |
---|
| 865 | <term> |
---|
| 866 | G4PSEnergyDeposit |
---|
| 867 | </term> |
---|
| 868 | <listitem><para> |
---|
| 869 | This scorer stores a sum of particles' energy deposits at each |
---|
| 870 | step in the cell. The particle weight is multiplied at each |
---|
| 871 | step. |
---|
| 872 | </para></listitem> |
---|
| 873 | </varlistentry> |
---|
| 874 | <varlistentry> |
---|
| 875 | <term> |
---|
| 876 | G4PSDoseDeposit |
---|
| 877 | </term> |
---|
| 878 | <listitem><para> |
---|
| 879 | In some cases, dose is a more convenient way to evaluate the |
---|
| 880 | effect of energy deposit in a cell than simple deposited energy. |
---|
| 881 | The dose deposit is defined by the sum of energy deposits at each |
---|
| 882 | step in a cell divided by the mass of the cell. The mass is |
---|
| 883 | calculated from the density and volume of the cell taken from the |
---|
| 884 | methods of <emphasis>G4VSolid</emphasis> and |
---|
| 885 | <emphasis>G4LogicalVolume</emphasis>. The particle |
---|
| 886 | weight is multiplied at each step. |
---|
| 887 | </para></listitem> |
---|
| 888 | </varlistentry> |
---|
| 889 | </variablelist> |
---|
| 890 | </para> |
---|
| 891 | |
---|
| 892 | <!-- ******* Bridgehead ******* --> |
---|
| 893 | <bridgehead renderas='sect4'> |
---|
| 894 | <emphasis role="bold">Current and flux scorers</emphasis> |
---|
| 895 | </bridgehead> |
---|
| 896 | |
---|
| 897 | <para> |
---|
| 898 | There are two different definitions of a particle's flow for a |
---|
| 899 | given geometry. One is a current and the other is a flux. In our |
---|
| 900 | scorers, the current is simply defined as the number of particles |
---|
| 901 | (with the particle's weight) at a certain surface or volume, while |
---|
| 902 | the flux takes the particle's injection angle to the geometry into |
---|
| 903 | account. The current and flux are usually defined at a surface, but |
---|
| 904 | volume current and volume flux are also provided. |
---|
| 905 | </para> |
---|
| 906 | |
---|
| 907 | <para> |
---|
| 908 | <variablelist><title></title> |
---|
| 909 | <varlistentry> |
---|
| 910 | <term> |
---|
| 911 | G4PSFlatSurfaceCurrent |
---|
| 912 | </term> |
---|
| 913 | <listitem><para> |
---|
| 914 | Flat surface current is a surface based scorer. The present |
---|
| 915 | implementation is limited to scoring only at the -Z surface of a |
---|
| 916 | <emphasis>G4Box</emphasis> solid. The quantity is defined by the number |
---|
| 917 | of tracks that reach the surface. The user must choose a direction of the |
---|
| 918 | particle to be scored. The choices are fCurrent_In, fCurrent_Out, |
---|
| 919 | or fCurrent_InOut, one of which must be entered as the second |
---|
| 920 | argument of the constructor. Here, fCurrent_In scores incoming |
---|
| 921 | particles to the cell, while fCurrent_Out scores only outgoing |
---|
| 922 | particles from the cell. fCurrent_InOut scores both directions. The |
---|
| 923 | current is multiplied by particle weight and is normalized for a |
---|
| 924 | unit area. |
---|
| 925 | </para></listitem> |
---|
| 926 | </varlistentry> |
---|
| 927 | <varlistentry> |
---|
| 928 | <term> |
---|
| 929 | G4PSSphereSurfaceCurrent |
---|
| 930 | </term> |
---|
| 931 | <listitem><para> |
---|
| 932 | Sphere surface current is a surface based scorer, and similar |
---|
| 933 | to the G4PSFlatSurfaceCurrent. The only difference is that the |
---|
| 934 | surface is defined at the <emphasis role="bold">inner surface</emphasis> |
---|
| 935 | of a G4Sphere solid. |
---|
| 936 | </para></listitem> |
---|
| 937 | </varlistentry> |
---|
| 938 | <varlistentry> |
---|
| 939 | <term> |
---|
| 940 | G4PSPassageCurrent |
---|
| 941 | </term> |
---|
| 942 | <listitem><para> |
---|
| 943 | Passage current is a volume-based scorer. The current is |
---|
| 944 | defined by the number of tracks that pass through the volume. A |
---|
| 945 | particle weight is applied at the exit point. A passage current is |
---|
| 946 | defined for a volume. |
---|
| 947 | </para></listitem> |
---|
| 948 | </varlistentry> |
---|
| 949 | <varlistentry> |
---|
| 950 | <term> |
---|
| 951 | G4PSFlatSurfaceFlux |
---|
| 952 | </term> |
---|
| 953 | <listitem><para> |
---|
| 954 | Flat surface flux is a surface based flux scorer. The surface |
---|
| 955 | flux is defined by the number of tracks that reach the surface. The |
---|
| 956 | expression of surface flux is given by the sum of W/cos(t)/A, where |
---|
| 957 | W, t and A represent particle weight, injection angle of particle |
---|
| 958 | with respect to the surface normal, and area of the surface. The |
---|
| 959 | user must enter one of the particle directions, fFlux_In, |
---|
| 960 | fFlux_Out, or fFlux_InOut in the constructor. Here, fFlux_In scores |
---|
| 961 | incoming particles to the cell, while fFlux_Out scores outgoing |
---|
| 962 | particles from the cell. fFlux_InOut scores both directions. |
---|
| 963 | </para></listitem> |
---|
| 964 | </varlistentry> |
---|
| 965 | <varlistentry> |
---|
| 966 | <term> |
---|
| 967 | G4PSCellFlux |
---|
| 968 | </term> |
---|
| 969 | <listitem><para> |
---|
| 970 | Cell flux is a volume based flux scorer. The cell flux is |
---|
| 971 | defined by a track length (L) of the particle inside a volume |
---|
| 972 | divided by the volume (V) of this cell. The track length is |
---|
| 973 | calculated by a sum of the step lengths in the cell. The expression |
---|
| 974 | for cell flux is given by the sum of (W*L)/V, where W is a particle |
---|
| 975 | weight, and is multiplied by the track length at each step. |
---|
| 976 | </para></listitem> |
---|
| 977 | </varlistentry> |
---|
| 978 | <varlistentry> |
---|
| 979 | <term> |
---|
| 980 | G4PSPassageCellFlux |
---|
| 981 | </term> |
---|
| 982 | <listitem><para> |
---|
| 983 | Passage cell flux is a volume based scorer similar to |
---|
| 984 | <emphasis>G4PSCellFlux</emphasis>. The only difference is that tracks |
---|
| 985 | which pass through a cell are taken into account. It means generated or |
---|
| 986 | stopped tracks inside the volume are excluded from the |
---|
| 987 | calculation. |
---|
| 988 | </para></listitem> |
---|
| 989 | </varlistentry> |
---|
| 990 | </variablelist> |
---|
| 991 | </para> |
---|
| 992 | |
---|
| 993 | <!-- ******* Bridgehead ******* --> |
---|
| 994 | <bridgehead renderas='sect4'> |
---|
| 995 | <emphasis role="bold">Other scorers</emphasis> |
---|
| 996 | </bridgehead> |
---|
| 997 | |
---|
| 998 | <para> |
---|
| 999 | <variablelist><title></title> |
---|
| 1000 | <varlistentry> |
---|
| 1001 | <term> |
---|
| 1002 | G4PSMinKinEAtGeneration |
---|
| 1003 | </term> |
---|
| 1004 | <listitem><para> |
---|
| 1005 | This scorer records the minimum kinetic energy of secondary |
---|
| 1006 | particles at their production point in the volume in an event. This |
---|
| 1007 | primitive scorer does not integrate the quantity, but records the |
---|
| 1008 | minimum quantity. |
---|
| 1009 | </para></listitem> |
---|
| 1010 | </varlistentry> |
---|
| 1011 | <varlistentry> |
---|
| 1012 | <term> |
---|
| 1013 | G4PSNofSecondary |
---|
| 1014 | </term> |
---|
| 1015 | <listitem><para> |
---|
| 1016 | This class scores the number of secondary particles generated |
---|
| 1017 | in the volume. The weight of the secondary track is taken into |
---|
| 1018 | account. |
---|
| 1019 | </para></listitem> |
---|
| 1020 | </varlistentry> |
---|
| 1021 | <varlistentry> |
---|
| 1022 | <term> |
---|
| 1023 | G4PSNofStep |
---|
| 1024 | </term> |
---|
| 1025 | <listitem><para> |
---|
| 1026 | This class scores the number of steps in the cell. A particle |
---|
| 1027 | weight is not applied. |
---|
| 1028 | </para></listitem> |
---|
| 1029 | </varlistentry> |
---|
| 1030 | <varlistentry> |
---|
| 1031 | <term> |
---|
| 1032 | G4PSCellCharge |
---|
| 1033 | </term> |
---|
| 1034 | <listitem><para> |
---|
| 1035 | This class scored the total charge of particles which has stoped |
---|
| 1036 | in the volume. |
---|
| 1037 | </para></listitem> |
---|
| 1038 | </varlistentry> |
---|
| 1039 | </variablelist> |
---|
| 1040 | </para> |
---|
| 1041 | |
---|
| 1042 | </sect2> |
---|
| 1043 | |
---|
| 1044 | |
---|
| 1045 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 1046 | <sect2 id="sect.Hits.G4VSDFil"> |
---|
| 1047 | <title> |
---|
| 1048 | <emphasis>G4VSDFilter</emphasis> and its derived classes |
---|
| 1049 | </title> |
---|
| 1050 | |
---|
| 1051 | <para> |
---|
| 1052 | <emphasis>G4VSDFilter</emphasis> is an abstract class that represents a track |
---|
| 1053 | filter to be associated with <emphasis>G4VSensitiveDetector</emphasis> or |
---|
| 1054 | <emphasis>G4VPrimitiveScorer</emphasis>. It defines a virtual method |
---|
| 1055 | |
---|
| 1056 | <informalexample> |
---|
| 1057 | <programlisting> |
---|
| 1058 | <emphasis>G4bool Accept(const G4Step*)</emphasis> |
---|
| 1059 | </programlisting> |
---|
| 1060 | </informalexample> |
---|
| 1061 | |
---|
| 1062 | that should return <emphasis>true</emphasis> if this particular step should be |
---|
| 1063 | scored by the <emphasis>G4VSensitiveDetector</emphasis> or |
---|
| 1064 | <emphasis>G4VPrimitiveScorer</emphasis>. |
---|
| 1065 | </para> |
---|
| 1066 | |
---|
| 1067 | <para> |
---|
| 1068 | While the user can implement his/her own filter class, Geant4 |
---|
| 1069 | version 8.0 provides the following concrete filter classes: |
---|
| 1070 | |
---|
| 1071 | <variablelist><title></title> |
---|
| 1072 | <varlistentry> |
---|
| 1073 | <term> |
---|
| 1074 | G4SDChargedFilter |
---|
| 1075 | </term> |
---|
| 1076 | <listitem><para> |
---|
| 1077 | All charged particles are accepted. |
---|
| 1078 | </para></listitem> |
---|
| 1079 | </varlistentry> |
---|
| 1080 | <varlistentry> |
---|
| 1081 | <term> |
---|
| 1082 | G4SDNeutralFilter |
---|
| 1083 | </term> |
---|
| 1084 | <listitem><para> |
---|
| 1085 | All neutral particles are accepted. |
---|
| 1086 | </para></listitem> |
---|
| 1087 | </varlistentry> |
---|
| 1088 | <varlistentry> |
---|
| 1089 | <term> |
---|
| 1090 | G4SDParticleFilter |
---|
| 1091 | </term> |
---|
| 1092 | <listitem><para> |
---|
| 1093 | Particle species which are registered to this filter object by |
---|
| 1094 | <emphasis>Add("particle_name")</emphasis> are accepted. More than one |
---|
| 1095 | species can be registered. |
---|
| 1096 | </para></listitem> |
---|
| 1097 | </varlistentry> |
---|
| 1098 | <varlistentry> |
---|
| 1099 | <term> |
---|
| 1100 | G4SDKineticEnergyFilter |
---|
| 1101 | </term> |
---|
| 1102 | <listitem><para> |
---|
| 1103 | A track with kinetic energy greater than or equal to EKmin and |
---|
| 1104 | smaller than EKmin is accepted. EKmin and EKmax should be defined |
---|
| 1105 | as arguments of the constructor. The default values of EKmin and |
---|
| 1106 | EKmax are zero and DBL_MAX. |
---|
| 1107 | </para></listitem> |
---|
| 1108 | </varlistentry> |
---|
| 1109 | <varlistentry> |
---|
| 1110 | <term> |
---|
| 1111 | G4SDParticleWithEnergyFilter |
---|
| 1112 | </term> |
---|
| 1113 | <listitem><para> |
---|
| 1114 | Combination of <emphasis>G4SDParticleFilter</emphasis> and |
---|
| 1115 | <emphasis>G4SDParticleWithEnergyFilter</emphasis>. |
---|
| 1116 | </para></listitem> |
---|
| 1117 | </varlistentry> |
---|
| 1118 | </variablelist> |
---|
| 1119 | </para> |
---|
| 1120 | |
---|
| 1121 | <para> |
---|
| 1122 | The use of the <emphasis>G4SDParticleFilter</emphasis> class is demonstrated |
---|
| 1123 | in <xref linkend="programlist_Hits_2" />, where filters which accept gamma, |
---|
| 1124 | electron, positron and electron/positron are defined. |
---|
| 1125 | </para> |
---|
| 1126 | |
---|
| 1127 | |
---|
| 1128 | </sect2> |
---|
| 1129 | |
---|
| 1130 | |
---|
| 1131 | <!-- ******************* Section (Level#2) ****************** --> |
---|
| 1132 | <sect2 id="sect.EvtBias.ScorImpRoul.Scor"> |
---|
| 1133 | <title> |
---|
| 1134 | Scoring for Event Biasing |
---|
| 1135 | </title> |
---|
| 1136 | |
---|
| 1137 | <para> |
---|
| 1138 | Scoring for Event Biasing (described in <xref linkend="sect.EvtBias" />) is a |
---|
| 1139 | very specific use case whereby particle weights and fluxes through importance |
---|
| 1140 | cells are required. The goals of the scoring technique are to: |
---|
| 1141 | |
---|
| 1142 | <itemizedlist spacing="compact"> |
---|
| 1143 | <listitem><para> |
---|
| 1144 | appraise particle quantities related to special regions or |
---|
| 1145 | surfaces, |
---|
| 1146 | </para></listitem> |
---|
| 1147 | <listitem><para> |
---|
| 1148 | be applicable to all "cells" (physical volumes or replicas) of |
---|
| 1149 | a given geometry, |
---|
| 1150 | </para></listitem> |
---|
| 1151 | <listitem><para> |
---|
| 1152 | be customizable. |
---|
| 1153 | </para></listitem> |
---|
| 1154 | </itemizedlist> |
---|
| 1155 | </para> |
---|
| 1156 | |
---|
| 1157 | <para> |
---|
| 1158 | Standard scoring must be provided for quantities such as tracks |
---|
| 1159 | entering a cell, average weight of entering tracks, energy of |
---|
| 1160 | entering tracks, and collisions inside the cell. |
---|
| 1161 | </para> |
---|
| 1162 | |
---|
| 1163 | <para> |
---|
| 1164 | A number of scorers have been created for this specific appliction: |
---|
| 1165 | </para> |
---|
| 1166 | |
---|
| 1167 | <para> |
---|
| 1168 | <variablelist><title></title> |
---|
| 1169 | <varlistentry> |
---|
| 1170 | <term> |
---|
| 1171 | G4PSNofCollision |
---|
| 1172 | </term> |
---|
| 1173 | <listitem><para> |
---|
| 1174 | This scorer records the number of collisions that occur within a scored volume/cell. |
---|
| 1175 | There is the additional possibility to take into account the track weight |
---|
| 1176 | whilst scoring the number of collisions, via the following command: |
---|
| 1177 | <informalexample> |
---|
| 1178 | <programlisting> |
---|
| 1179 | G4PSNofCollision* scorer1 = new G4PSNofCollision(psName="CollWeight"); |
---|
| 1180 | scorer1->Weighted(true); |
---|
| 1181 | </programlisting> |
---|
| 1182 | </informalexample> |
---|
| 1183 | </para></listitem> |
---|
| 1184 | </varlistentry> |
---|
| 1185 | <varlistentry> |
---|
| 1186 | <term> |
---|
| 1187 | G4PSPopulation |
---|
| 1188 | </term> |
---|
| 1189 | <listitem><para> |
---|
| 1190 | This scores the number of tracks within in a given cell per event. |
---|
| 1191 | </para></listitem> |
---|
| 1192 | </varlistentry> |
---|
| 1193 | <varlistentry> |
---|
| 1194 | <term> |
---|
| 1195 | G4PSTrackLength |
---|
| 1196 | </term> |
---|
| 1197 | <listitem><para> |
---|
| 1198 | The track lengths within a cell are measured and if, additionally, the result is desired |
---|
| 1199 | to be weighted then the following code has to be implemented: |
---|
| 1200 | <informalexample> |
---|
| 1201 | <programlisting> |
---|
| 1202 | G4PSTrackLength* scorer5 = new G4PSTrackLength(psName="SLW"); |
---|
| 1203 | scorer5->Weighted(true); |
---|
| 1204 | </programlisting> |
---|
| 1205 | </informalexample> |
---|
| 1206 | Further if the energy track flux is required then the following should be |
---|
| 1207 | implemented: |
---|
| 1208 | <informalexample> |
---|
| 1209 | <programlisting> |
---|
| 1210 | G4PSTrackLength* scorer6 = new G4PSTrackLength(psName="SLWE"); |
---|
| 1211 | scorer6->Weighted(true); |
---|
| 1212 | scorer6->MultiplyKineticEnergy(true); |
---|
| 1213 | MFDet->RegisterPrimitive(scorer6); |
---|
| 1214 | </programlisting> |
---|
| 1215 | </informalexample> |
---|
| 1216 | |
---|
| 1217 | Alternatively to measure the flux per unit velocity then: |
---|
| 1218 | <informalexample> |
---|
| 1219 | <programlisting> |
---|
| 1220 | G4PSTrackLength* scorer7 = new G4PSTrackLength(psName="SLW_V"); |
---|
| 1221 | scorer7->Weighted(true); |
---|
| 1222 | scorer7->DivideByVelocity(true); |
---|
| 1223 | MFDet->RegisterPrimitive(scorer7); |
---|
| 1224 | </programlisting> |
---|
| 1225 | </informalexample> |
---|
| 1226 | |
---|
| 1227 | Finally to measure the flux energy per unit velocity then: |
---|
| 1228 | <informalexample> |
---|
| 1229 | <programlisting> |
---|
| 1230 | G4PSTrackLength* scorer8 = new G4PSTrackLength(psName="SLWE_V"); |
---|
| 1231 | scorer8->Weighted(true); |
---|
| 1232 | scorer8->MultiplyKineticEnergy(true); |
---|
| 1233 | scorer8->DivideByVelocity(true); |
---|
| 1234 | MFDet->RegisterPrimitive(scorer8); |
---|
| 1235 | </programlisting> |
---|
| 1236 | </informalexample> |
---|
| 1237 | </para></listitem> |
---|
| 1238 | </varlistentry> |
---|
| 1239 | </variablelist> |
---|
| 1240 | </para> |
---|
| 1241 | |
---|
| 1242 | |
---|
| 1243 | </sect2> |
---|
| 1244 | |
---|
| 1245 | </sect1> |
---|