| Geant4 Cross Reference |
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2 =========================================
3 Geant4 - an Object-Oriented Toolkit for S
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6
7
8 field05 Example
9 ---------------
10
11 This example checks so-called "spin-froze
12 There is a good example article hep-ph/00
13 This article discusses about how to cance
14 applying an electric field.
15
16 1) beta is muon velocity,
17 2) B is an uniform magnetic field and \ve
18 "." means scalar product,
19 3) Radial electric field (E) in the lab f
20 4) a=(g-2)/2 is muon anomalous magnetic m
21
22 The required electric field to cancel the
23 E=a*B*light_c*gamma**2*beta.
24
25 In case of gamma=5 and B=0.24 Tesla, the
26 E=2 MV/m.
27
28 "Spin-frozen" happens when spin rotation
29 are same. In this case, both cycles shoul
30
31 See also:
32 http://research.kek.jp/people/hiromi/MyHo
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34
35 Credit goes to Hiromi Iinuma from KEK.
36
37 **************
38 *Classes Used*
39 **************
40
41 1 - main()
42
43 See field05.cc.
44
45 2- GEOMETRY DEFINITION
46
47 as simple world G4Box with a G4ElectroMagn
48 propagating both spin and momentum (G4EqEM
49 with G4ClassicalRK4(fEquation,12) and
50 Bz = 0.24*tesla;
51 Er = 2.113987E+6*volt/m;
52
53 3- AN EVENT: THE PRIMARY GENERATOR
54
55 use mu+ G4ParticleGun with Pmu = 517.6*MeV
56 and aligned spin and momentum direction
57
58 4- PHYSICS
59
60 RegisterPhysics(new G4SpinDecayPhysics());
61 RegisterPhysics(new G4StepLimiterPhysics()
62
63 G4SpinDecayPhysics defines muon decay mode
64 G4StepLimiterPhysics defines G4StepLimiter
65
66 5- User Action Classes
67
68 SteppingAction:
69 G4Exception when the cosine of the
70 the spin and the momentum is < (1.
71
72 6- HOW TO START ?
73
74 - Execute field05 in 'batch' mode from
75 % field05 field05.in > field.o
76
77 - Execute field05 in 'interactive' mod
78 % field05
79 ....
80 Idle> type your commands, for
81 Idle> run/beamOn 1
82 ....