CERN Program Library Long Writeup W5013 - CERNLIB ...

More documents

Recommendations

Info

Geant 3.21 GEANT User’s Guide GEOM010 Origin : Submitted: 10.03.94 Revision : Revised: 10.03.94 Documentation : S.Giani, S.Ravndal Tracking inside volumes and optimisation The tracking of particles through the geometrical data structure is the key functionality of GEANT. At every particle’s step, the program must find the volume where the particle is (GTMEDI) and the next boundary it will cross (GTNEXT). This can take about 60% of the total simulation time (even for detectors described in an optimized way); therefore, a new logic has been introduced to minimize the time spent for the search in the geometrical tree. 1 Virtual divisions Instead of a linear or binary search (time spent proportional or logarithmic with the number of volumes, respectively), a ‘direct access’ technique has been developed to make the time basically independent from the number of volumes. Every volume containing other volumes is ‘virtually’ divided in equal slices at initialization time via the call to GGCLOS (the best axis is computed automatically). For each slice, a data structure is filled with a list of the volumes identifiers intersecting such slice. Slices with identical lists are pointing to the same contents and are collected. At tracking time it is immediate to find in which slice the particle is and only its contents have to be checked. The same is true to find the next boundary to be crossed: only if the intersection point with a content lies outside the current collection of slices, the next one will be checked. The algorithm gives in average about a factor 2 in speed for the overall simulation in the large detectors. It also minimizes the dependency of the performance on the skill and experience of the programmer and allows a fast tracking even in geometrical structures received from CAD systems. 2 Other optimisation tools The following facilities are kept for backward compatibility reasons. If called by the user, these optimisation tools are called at initialisation time, but not used at tracking time. Instead, the new optimisation using ’virtual divisions’ is performed. If the user wants to use the older optimisation tools, he can recompile GEANT 3.21 using the PATCHY flag +OLD. 1. GSORD/GGORD From the position of the contents inside a given volume, the subroutine GSORD computes fictitious boundaries along the specified coordinate, simulating a division with irregular step size. A binary search technique is used to identify within which pseudo-cell the current point is. The slow process of computing whether the point is inside or outside the contents is therefore limited to the few (if any) volumes overlapping with that pseudo-cell, as sketched in fig 20. The coordinate selected for the pseudo division can be any of X, Y, Z, R xy , R, φ or θ;. For a given volume, the call to GSORD has to come after all its first level contents have been positioned. 2. GSNEXT/GSNEAR when a particle exits from a daugther of a mother volume, the contents are scanned initially in the order in which they have been positioned, and the user should take care over the best sequence of GSPOS calls. However, when the particle comes back inside the mother from any one of the contents, it is usually possible to limit the search to the neighbour contents. The subroutines GSNEXT/GSNEAR permit the user to inject, at initialisation time, for each content in turn, the list of neighbours to search for. GSNEAR is recommended, GSNEXT is kept for backward, compatibility and has a different default option. A proper use of this facility can reduce the search time significantly. 106 GEOM010 – 1
0 1 2 1 0 1 0 1 2 3 4 5 6 7 Figure 20: Example of pseudo-cells created by GSORD 3. GSUNEA/GUNEAR The volumes to be checked when exiting from one daughter can depend on the direction and position of the exiting particles. To optimise tracking taking into account these dynamic features, the user can code the GUNEAR routine, and inform GEANT that it has to use it at tracking time by calling the GSUNEA routine. GEOM010 – 2 107
Page 1 and 2:
CERN Program Library Long Writeup W
Page 3 and 4:
Chapter 1: Catalog of Geant section
Page 5 and 6:
IOPA500 KINE001 KINE100 KINE199 KIN
Page 7 and 8:
Geant 3.21 GEANT User’s Guide AAA
Page 9 and 10:
The routines made available for GEA
Page 11 and 12:
outines, then you can type the foll
Page 13 and 14:
AAAA Bibliography [1] H.J. Klein an
Page 15 and 16:
2 Event simulation framework The fr
Page 17 and 18:
• after each tracking step along
Page 19 and 20:
GUDIGI GUOUT GTRIGC UGLAST GLAST GU
Page 21 and 22:
Particles JPART Materials JMATE/JTM
Page 23 and 24:
3 Summary of GEANT data records 3.1
Page 25 and 26:
3.4 User applications KEY N I VAR S
Page 27 and 28:
Geant 3.16 GEANT User’s Guide BAS
Page 29 and 30:
Page 31 and 32:
SUBROUTINE UGEOM + (’TGT ’,2,
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
LQ(JHEAD-1) user link IQ(JHEAD+1) I
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
VALUE = GARNDM (DUMMY) DUMMY (REAL)
Page 47 and 48:
Geant 3.16 GEANT User’s Guide CON
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58: 1 Energy binning IDECAD Bin number
Page 59 and 60: Geant 3.16 GEANT User’s Guide CON
Page 65 and 66: Particle No. Mass(GeV) Charge Life
Page 69 and 70: ¯Ω + ¯Ξ 0 π + 23.60 ¯ΛK + 67
Page 71 and 72: Geant 3.16 GEANT User’s Guide DRA
Page 73 and 74: The main drawing routines are: GDRA
Page 77 and 78: Another feature which is available
Page 79 and 80: z y x C CHARACTER*4 CHNAMS(5) INTEG
Page 83 and 84: CALL GDRAWC(’OPAL’,2,0.,10.,10.
Page 85 and 86: CALL GSATT(’HB’,’FILL’,3) C
Page 87 and 88: CALL GDRAW(’CAVE’,40.,40.,0.,10
Page 93 and 94: Figure 16: Example of use of GDSPEC
Page 95 and 96: CALL GDOPEN(3) CALL GDRAWC(’ALEF
Page 97 and 98: 6 NKVIEW IVIEW JDRAW NKVIEW JV = IB
Page 99 and 100: SHAD EDGE when HIDE is ON, selects
Page 101 and 102: x1xxxx 1xxxxx add the text EVENT NR
Page 103 and 104: DRAW Bibliography [1] R.Bock et al.
Page 105 and 106: 2 Volumes with contents A volume ca
Page 107: The user can position a volume thro
Page 111 and 112: 2 Divisions along arbitrary axis As
Page 113 and 114: 9.BL2 half-length along x of the si
Page 115 and 116: 1.DZ half-length along the z axis;
Page 117 and 118: ECAL BOX specifications 18/11/93 EC
Page 119 and 120: ECAL SPHE specifications 18/11/93 E
Page 121 and 122: Geant 3.16 GEANT User’s Guide GEO
Page 123 and 124: • if the CHONLY flag is set to MA
Page 127 and 128: y y x x y y y y z z x x z z y y x x
Page 129 and 130: CAVE PAR1 specifications 20/10/94 y
Page 143 and 144: Dynamic ordering The list of neighb
Page 151 and 152: are represented by their values. A
Page 153 and 154: Where • @302 is the block number
Page 155 and 156: GEOM Bibliography [1] French Standa
Page 157 and 158: Geant 3.16 GEANT User’s Guide HIT
Page 159 and 160:
Geant 3.16 GEANT User’s Guide HIT
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
ITRA NUMBV HITS NHITS (INTEGER) is
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
HITS Bibliography 175 HITS510 - 3
Page 179 and 180:
Geant 3.16 GEANT User’s Guide IOP
Page 181 and 182:
0 if only IER] structures read in o
Page 183 and 184:
Geant 3.16 GEANT User’s Guide IOP
Page 185 and 186:
IOPA Bibliography [1] J.Zoll. ZEBRA
Page 187 and 188:
Geant 3.16 GEANT User’s Guide KIN
Page 189 and 190:
Page 191 and 192:
NTRACK ITRA JKINE NTRACK JK 1 2 3 4
Page 193 and 194:
Page 195 and 196:
Geant 3.16 GEANT User’s Guide PHY
Page 197 and 198:
Below are listed the data record ke
Page 199 and 200:
Computation of total crosssection o
Page 201 and 202:
7. Update the number of interaction
Page 203 and 204:
1= generation of secondaries enable
Page 205 and 206:
DEEMAX The formula used by GEANT is
Page 207 and 208:
The second problem has been solved
Page 209 and 210:
Page 211 and 212:
GPHYSI Initialisation of physics pr
Page 213 and 214:
Page 215 and 216:
• the mean number of tries is not
Page 217 and 218:
as function of the variable u = Eθ
Page 219 and 220:
Page 221 and 222:
GEANT 3.16 GEANT User’s Guide PHY
Page 223 and 224:
where N Z(Z i ) A(A i ) ρ σ Avoga
Page 225 and 226:
Word # PHFN bank (data area, contin
Page 227 and 228:
2 Method If the energy of the radia
Page 229 and 230:
The Auger or Coster-Kronig transiti
Page 231 and 232:
Page 233 and 234:
where: n number of energy bins q i
Page 235 and 236:
• Case dielectric → metal. The
Page 237 and 238:
| ⃗ k| = | ⃗ k ′′ | = k =
Page 239 and 240:
Case dielectric → metal In this c
Page 241 and 242:
5 Processes involving Čerenkov pho
Page 243 and 244:
Much of the difficulty in approxima
Page 245 and 246:
CALL GMOLIE (OMEGA,BETA2,DIN*) OMEG
Page 247 and 248:
where λ 0 = ¯h/p Compton waveleng
Page 249 and 250:
2.3 Sampling of the distribution fu
Page 251 and 252:
X 0 is the radiation length. From (
Page 253 and 254:
where we have set Θ=θ/χ α . To
Page 255 and 256:
The variable DCUTE in common /GCCUT
Page 257 and 258:
2.2 Total cross-sections The integr
Page 259 and 260:
For the other charged particles the
Page 261 and 262:
POTI POTIL (REAL) average ionisatio
Page 263 and 264:
where φ(λ) = 1 ∫ c+i∞ exp (u
Page 265 and 266:
Counts 900 800 Landau 700 40 600 20
Page 267 and 268:
Fast simulation for n 3 ≥ 16 If t
Page 269 and 270:
Page 271 and 272:
ξ/E Max (hereafter κ) relative im
Page 273 and 274:
Page 275 and 276:
ln(∫ σ γ dE/norm.factor) -4 -6
Page 277 and 278:
Page 279 and 280:
VALUE = GBFSIG (T,C) GBFSIG calcula
Page 281 and 282:
∆σ σ = { 12 − 15% for T ≤ 1
Page 283 and 284:
T(MeV) C Pb ∆El 0 ∆E l ∆σ l
Page 285 and 286:
Page 287 and 288:
1. sample x from 1 1 ln 1 x c x set
Page 289 and 290:
Page 291 and 292:
E bind , eV 10 5 10 20 30 40 50 60
Page 293 and 294:
Page 295 and 296:
Page 297 and 298:
Page 299 and 300:
Page 301 and 302:
eV). At present the values recommen
Page 303 and 304:
calculated dE dx − dE measured dx
Page 305 and 306:
Page 307 and 308:
Figure 43: Stopping powers in Carbo
Page 309 and 310:
esults can be seen in table 2 and 3
Page 311 and 312:
VALUE = GBRSGM (Z,T,BCUT) Z T BCUT
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
The functions F i (Z,X,Y) (i = σ,
Page 319 and 320:
where, (a − 1) 1 f(ν) = ( ) 1 ν
Page 321 and 322:
where: Γ = kα 2π [ ɛ = W E 1 1
Page 323 and 324:
NLM DENS CORR IPART (INTEGER) numbe
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
Hydrogen (bound) Sodium Copper Hydr
Page 331 and 332:
[25] M. Gavrila. Relativistic l-she
Page 333 and 334:
[78] R.W.Williams. Fundamental Form
Page 335 and 336:
[CONS]). Usually, this is done toge
Page 337 and 338:
Geant 3.16 GEANT User’s Guide TRA
Page 339 and 340:
Page 341 and 342:
VECT,SNEXT,SAFETY Compute distance
Page 343 and 344:
VECT,SNEXT,SAFETY Compute distance
Page 345 and 346:
VECT,SNEXT,SAFETY Compute SFIELD,SM
Page 347 and 348:
SUBROUTINE GUSTEP +SEQ,GCKING,GCVOL
Page 349 and 350:
Page 351 and 352:
Page 353 and 354:
CALL GRKUTA (CHARGE,STEP,VECT,VOUT*
Page 355 and 356:
Geant 3.16 GEANT User’s Guide XIN
Page 357 and 358:
Clicking then on the right button o
Page 359 and 360:
Page 361 and 362:
YMED R “ Center Y coordinate ”
Page 363 and 364:
HIDE is ON, the detector can be exp
Page 365 and 366:
e drawn. NAMNUM contain the arrays
Page 367 and 368:
following levels (red arrows) and o
Page 369 and 370:
Draw a polyline of ’npoint’ poi
Page 371 and 372:
a dynamical 3-D analysis of the sim
Page 373 and 374:
1. position the cursor at (uz0,vz0)
Page 375 and 376:
CHUSET C “User set identifier”
Page 377 and 378:
Set current attribute. 4.8 SSETVA [
Page 379 and 380:
CALL GDCOL(-abs(icol)) 4.12 LWID lw
Page 381 and 382:
5 GEANT/GEOMETRY Geometry commands.
Page 383 and 384:
Print matrixes’ specifications. 5
Page 385 and 386:
6 GEANT/CREATE It creates volumes o
Page 387 and 388:
YES NO 6.7 SCONS name numed inrdw o
Page 389 and 390:
7 GEANT/CONTROL Control commands. 7
Page 391 and 392:
To change lout in /GCUNIT/ Note: un
Page 393 and 394:
IPART I “Particle number” NAPAR
Page 395 and 396:
8.5 CDIR [ chpath chopt ] CHPATH C
Page 397 and 398:
9 GEANT/FZ ZEBRA/FZ commands 9.1 FZ
Page 399 and 400:
Check the structure of one or more
Page 401 and 402:
FACTL R “Scale factor for SL” D
Page 403 and 404:
12 GEANT/PHYSICS Commands to set ph
Page 405 and 406:
Possible IDRAY values are: 0 1 2 To
Page 407 and 408:
12.14 PAIR [ ipair ] IPAIR C “Fla
Page 409 and 410:
PPCUTM R “Cut for e+e- pairs by m
Page 411 and 412:
LGET_15 C “user word” LGET_16 C
Page 413 and 414:
13.6 GEOM [ lgeom˙1 lgeom˙2 lgeom
Page 415 and 416:
LSTAT_7 C “user word” LSTAT_8 C
Page 417 and 418:
Page 419 and 420:
XINT Bibliography [1] R.Brun and P.
Page 421 and 422:
This common contains the threshold
Page 423 and 424:
ITR3D track being scanned (used tog
Page 425 and 426:
NCLAS1 NCLAS2 NCLAS3 IHOLE CGXMIN C
Page 427 and 428:
* PARAMETER (MAXJMP=30) COMMON/GCJU
Page 429 and 430:
GYMAX GZMIN GZMAX GXXXX GYYYY GZZZZ
Page 431 and 432:
DENS density of current material in
Page 433 and 434:
RADDEG radiants to degrees conversi
Page 435 and 436:
PCUTNE parameterisation threshold f
Page 437 and 438:
SMULS SOMULS STMULS DPHYS3 ILABS SL
Page 439 and 440:
NTETA TETMIN TETMAX MODTET number o
Page 441 and 442:
S2 S3 SS1 SS2 SS3 LEP IPORLI ISUBLI
Page 443 and 444:
CFIELD constant for field step eval
Page 445 and 446:
NEXT 1 particle has reached the bou
Page 447 and 448:
C COMMON/GCVOL2/NLEVE2,NAMES2(15),N
Page 449 and 450:
STEP PLIN PLOG BE2 PLASM TRNSMA BOS
Page 451 and 452:
C ESHELL - Shells potentials in eV
Page 453 and 454:
Geant 3.11 GEANT User’s Guide ZZZ
Page 455 and 456:
GFKINE KINE001, KINE100, KINE199 GF
Page 457 and 458:
GPSTAT GEOM700 GPTMED CONS001, CONS
Page 459 and 460:
ZZZZ Bibliography [1] T.Sjöstrand
Page 461 and 462:
CDRSGA, 297 CGMULO, 221 CHANGEWK, 3
Page 463 and 464:
GEANT/DRAWING/KHITS, 372 GEANT/DRAW
Page 465 and 466:
GPART, 13, 46, 61, 293 GPCXYZ, 40,
Page 467:
PATCHY, 278 PCUTS, 399 PDIGI, 389 P
show all

CERN Program Library Long Writeup W5013 - CERNLIB ...

Create successful ePaper yourself

Delete template?

Save as template?