| Geant4 Cross Reference |
1 ---------------------------------------------- 1 -------------------------------------------------------------------
2 2
3 ========================================= 3 =========================================================
4 Geant4 - an Object-Oriented Toolkit for S 4 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
5 ========================================= 5 =========================================================
6 6
7 field03 7 field03
8 ------- 8 -------
9 9
10 Example of tracking in magnetic field wher 10 Example of tracking in magnetic field where field associated
11 to selected logical volumes varies. 11 to selected logical volumes varies.
12 12
13 A global and a local magnetic field are de << 13 A global and a local magnetic field are defined in the F03FieldSetup class, which object
14 the ConstructSDandField() method in the F0 << 14 is created in the ConstructSDandField() function in the F03DetectorConstruction
15 using the G4FieldBuilder class. << 15 class. The local magnetic field is set to the "Radiator" volume.
16 The local magnetic field is set to the "Ra << 16 The interactive commands are implemented in F03FieldMessenger.
17 17
18 The interactive commands, under the /field <<
19 the instantiation of G4FieldBuilder in the <<
20 18
21 1- GEOMETRY DEFINITION 19 1- GEOMETRY DEFINITION
22 20
23 The "Absorber" is a solid made of a given ma 21 The "Absorber" is a solid made of a given material.
24 22
25 Three parameters define the absorber : 23 Three parameters define the absorber :
26 - the material of the absorber, 24 - the material of the absorber,
27 - the thickness of an absorber, 25 - the thickness of an absorber,
28 - the transverse size of the absorber (the i 26 - the transverse size of the absorber (the input face is a square).
29 27
30 The volume "World" contains the "Absor 28 The volume "World" contains the "Absorber".
31 In this test the parameters of the "Wo 29 In this test the parameters of the "World" can be changed , too.
32 30
33 A transverse global uniform magnetic field 31 A transverse global uniform magnetic field can be applied.
34 In addition, the "Radiator" volume, which is 32 In addition, the "Radiator" volume, which is placed in geometry next
35 to the absorber, has a local magnetic fiel 33 to the absorber, has a local magnetic field.
36 34
37 The default geometry is constructed in F03De 35 The default geometry is constructed in F03DetectorConstruction class,
38 but all the parameters can be changed via 36 but all the parameters can be changed via
39 the commands defined in the F03DetectorMesse 37 the commands defined in the F03DetectorMessenger class.
40 38
41 2- AN EVENT : THE PRIMARY GENERATOR 39 2- AN EVENT : THE PRIMARY GENERATOR
42 40
43 The primary kinematic consists of a single p 41 The primary kinematic consists of a single particle which hits the
44 absorber perpendicular to the input face. Th 42 absorber perpendicular to the input face. The type of the particle
45 and its energy are set in the F03PrimaryGene 43 and its energy are set in the F03PrimaryGeneratorAction class, and can
46 be changed via the G4 build-in commands of G 44 be changed via the G4 build-in commands of G4ParticleGun class (see
47 the macros provided with this example). 45 the macros provided with this example).
48 46
49 It is also possible to change the position 47 It is also possible to change the position of the primary particle vertex
50 or activate its randomization via the comm 48 or activate its randomization via the commands defined in the
51 F01PrimaryGeneratorMessenger class. 49 F01PrimaryGeneratorMessenger class.
52 50
53 A RUN is a set of events. 51 A RUN is a set of events.
54 52
55 3- DETECTOR RESPONSE 53 3- DETECTOR RESPONSE
56 54
57 A HIT is a record, event per event , of all 55 A HIT is a record, event per event , of all the
58 informations needed to simulate and analyse 56 informations needed to simulate and analyse the detector response.
59 57
60 In this example a F03CalorHit is defined as 58 In this example a F03CalorHit is defined as a set of 2 informations:
61 - the total energy deposit in the absorber, 59 - the total energy deposit in the absorber,
62 - the total tracklength of all charged parti 60 - the total tracklength of all charged particles in the absorber,
63 61
64 Therefore the absorber is declared 62 Therefore the absorber is declared
65 'sensitive detector' (SD), see F03Calorimete 63 'sensitive detector' (SD), see F03CalorimeterSD, which means they can contribute to the hit.
66 64
67 4- PHYSICS LIST 65 4- PHYSICS LIST
68 66
69 The particle's type and the physic proces 67 The particle's type and the physic processes which will be available
70 in this example are set in the FTFP_BERT 68 in this example are set in the FTFP_BERT physics list. This physics list
71 requires data files for electromagnetic a 69 requires data files for electromagnetic and hadronic processes.
72 See more on installation of the datasets 70 See more on installation of the datasets in Geant4 Installation Guide,
73 71
74 5- HOW TO START ? 72 5- HOW TO START ?
75 73
76 - Execute field03 in 'batch' mode from macro 74 - Execute field03 in 'batch' mode from macro files e.g.
77 % ./field03 field03.in 75 % ./field03 field03.in
78 76
79 - Execute field03 in 'interactive' mode with 77 - Execute field03 in 'interactive' mode with visualization e.g.
80 % ./field03 78 % ./field03
81 .... 79 ....
82 Idle> /run/beamOn 1 80 Idle> /run/beamOn 1
83 .... 81 ....