| Geant4 Cross Reference |
>> 1 $Id: README 68021 2013-03-13 13:36:07Z gcosmo $
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2 3
3 ========================================= 4 =========================================================
4 Geant4 - an Object-Oriented Toolkit for S 5 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
5 ========================================= 6 =========================================================
6 7
7 field03 8 field03
8 ------- 9 -------
9 10
10 Example of tracking in magnetic field wher 11 Example of tracking in magnetic field where field associated
11 to selected logical volumes varies. 12 to selected logical volumes varies.
12 13
13 A global and a local magnetic field are de << 14
14 the ConstructSDandField() method in the F0 <<
15 using the G4FieldBuilder class. <<
16 The local magnetic field is set to the "Ra <<
17 <<
18 The interactive commands, under the /field <<
19 the instantiation of G4FieldBuilder in the <<
20 <<
21 1- GEOMETRY DEFINITION 15 1- GEOMETRY DEFINITION
22 << 16
23 The "Absorber" is a solid made of a given ma << 17 The "absorber" is a solid made of a given material.
24 << 18
25 Three parameters define the absorber : 19 Three parameters define the absorber :
26 - the material of the absorber, 20 - the material of the absorber,
27 - the thickness of an absorber, 21 - the thickness of an absorber,
28 - the transverse size of the absorber (the i << 22 - the transverse size of the absorber (the input face is a square).
29 << 23
30 The volume "World" contains the "Absor << 24 The volume "World" contains the "absorber".
31 In this test the parameters of the "Wo 25 In this test the parameters of the "World" can be changed , too.
32 26
33 A transverse global uniform magnetic field << 27 In addition a transverse uniform magnetic field can be applied.
34 In addition, the "Radiator" volume, which is << 28
35 to the absorber, has a local magnetic fiel <<
36 <<
37 The default geometry is constructed in F03De 29 The default geometry is constructed in F03DetectorConstruction class,
38 but all the parameters can be changed via 30 but all the parameters can be changed via
39 the commands defined in the F03DetectorMesse 31 the commands defined in the F03DetectorMessenger class.
40 << 32
41 2- AN EVENT : THE PRIMARY GENERATOR 33 2- AN EVENT : THE PRIMARY GENERATOR
42 << 34
43 The primary kinematic consists of a single p 35 The primary kinematic consists of a single particle which hits the
44 absorber perpendicular to the input face. Th 36 absorber perpendicular to the input face. The type of the particle
45 and its energy are set in the F03PrimaryGene 37 and its energy are set in the F03PrimaryGeneratorAction class, and can
46 be changed via the G4 build-in commands of G 38 be changed via the G4 build-in commands of G4ParticleGun class (see
47 the macros provided with this example). 39 the macros provided with this example).
48 << 40
49 It is also possible to change the position <<
50 or activate its randomization via the comm <<
51 F01PrimaryGeneratorMessenger class. <<
52 <<
53 A RUN is a set of events. 41 A RUN is a set of events.
54 << 42
55 3- DETECTOR RESPONSE 43 3- DETECTOR RESPONSE
56 44
57 A HIT is a record, event per event , of all << 45
>> 46 A HIT is a record, event per event , of all the
58 informations needed to simulate and analyse 47 informations needed to simulate and analyse the detector response.
59 << 48
60 In this example a F03CalorHit is defined as 49 In this example a F03CalorHit is defined as a set of 2 informations:
61 - the total energy deposit in the absorber, 50 - the total energy deposit in the absorber,
62 - the total tracklength of all charged parti << 51 - the total tracklength of all charged particles in the absorber,
63 << 52
64 Therefore the absorber is declared 53 Therefore the absorber is declared
65 'sensitive detector' (SD), see F03Calorimete 54 'sensitive detector' (SD), see F03CalorimeterSD, which means they can contribute to the hit.
66 55
67 4- PHYSICS LIST << 56
68 << 57 4- PHYSICS DEMO
69 The particle's type and the physic proces << 58
70 in this example are set in the FTFP_BERT << 59 The particle's type and the physic processes which will be available
71 requires data files for electromagnetic a << 60 in this example are set in F03PhysicsList class.
72 See more on installation of the datasets << 61
>> 62 The messenger classes, F03PhysicsListMessenger, introduce interactive commands . Using these
>> 63 commands the geometry of the detector, the data of the primary
>> 64 particle, etc. can be changed.
>> 65
73 66
74 5- HOW TO START ? 67 5- HOW TO START ?
75 << 68
76 - Execute field03 in 'batch' mode from macro << 69 - execute field03 in 'batch' mode from macro files e.g.
77 % ./field03 field03.in << 70 % field03 field03.in
78 << 71
79 - Execute field03 in 'interactive' mode with << 72 - execute field03 in 'interactive' mode with visualization e.g.
80 % ./field03 << 73 % field03
81 .... 74 ....
82 Idle> /run/beamOn 1 << 75 Idle> /control/execute vis.mac
83 .... 76 ....