1 '''Defines the BeamDump class for theia.'''
2
3
4
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8
9
10 import numpy as np
11 from ..helpers import settings
12 from ..helpers.geometry import rectToSph, linePlaneInter, lineCylInter
13 from ..helpers.units import deg, pi
14 from .component import SetupComponent
15
17 '''
18
19 BeamDump class.
20
21 This class represents components on which rays stop. They have cylindrical
22 symmetry and stop beams on all their faces. They can represent baffles
23 for example.
24
25 *=== Attributes ===*
26 SetupCount (inherited): class attribute, counts all setup components.
27 [integer]
28 Name: class attribute. [string]
29 HRCenter (inherited): center of the principal face of the BeamDump in space.
30 [3D vector]
31 HRnorm (inherited): normal unitary vector the this principal face,
32 supposed to point outside the media. [3D vector]
33 Thick (inherited): thickness of the dump, counted in opposite direction to
34 HRNorm. [float]
35 Dia (inherited): diameter of the component. [float]
36 Ref (inherited): reference string (for keeping track with the lab). [string]
37
38 '''
39 Name = "BeamDump"
40 - def __init__(self, X = 0., Y = 0., Z = 0., Theta = pi/2., Phi = 0.,
41 Ref = None,
42 Thickness = 2.e-2, Diameter = 5.e-2):
43 '''BeamDump initializer.
44
45 Parameters are the attributes.
46
47 Returns a BeamDump.
48
49 '''
50
51 Thickness = float(Thickness)
52 Diameter = float(Diameter)
53
54
55 Norm = np.array([np.sin(Theta)*np.cos(Phi),
56 np.sin(Theta) * np.sin(Phi),
57 np.cos(Theta)], dtype = np.float64)
58
59 HRCenter = np.array([X, Y, Z], dtype = np.float64)
60
61
62 super(BeamDump, self).__init__(Ref = Ref,
63 Diameter = Diameter, HRCenter = HRCenter, HRNorm = Norm,
64 Thickness = Thickness)
65
67 '''Return the list of lines needed to print the object.
68 '''
69 ans = []
70 ans.append("BeamDump: %s {" %self.Ref)
71 ans.append("Thick: %sm" %str(self.Thick))
72 ans.append("Diameter: %sm" %str(self.Dia))
73 ans.append("Center: %s" %str(self.HRCenter))
74 sph = rectToSph(self.HRNorm)
75 ans.append("Norm: (%s, %s)deg" %(str(sph[0]/deg), str(sph[1]/deg)))
76 ans.append("}")
77
78 return ans
79
81 '''Determine if a beam hits the BeamDump.
82
83 This uses the line***Inter functions from the geometry module to find
84 characteristics of impact of beams on beamdumps.
85
86 beam: incoming beam. [GaussianBeam]
87
88 Returns a dictionary with keys:
89 'isHit': whether the beam hits the dump. [boolean]
90 'intersection point': point in space where it is first hit.
91 [3D vector]
92 'face': to indicate which face is first hit, can be 'HR', 'AR' or
93 'side'. [string]
94 'distance': geometrical distance from beam origin to impact. [float]
95
96 '''
97
98 noInterDict = {'isHit': False,
99 'intersection point': np.array([0., 0., 0.],
100 dtype=np.float64),
101 'face': None,
102 'distance': 0.}
103
104
105 HRDict = linePlaneInter(beam.Pos, beam.Dir, self.HRCenter,
106 self.HRNorm, self.Dia)
107
108 SideDict =lineCylInter(beam.Pos, beam.Dir,
109 self.HRCenter, self.HRNorm,
110 self.Thick, self.Dia)
111
112 ARCenter = self.HRCenter - self.Thick*self.HRNorm
113
114 ARDict = linePlaneInter(beam.Pos, beam.Dir, ARCenter,
115 - self.HRNorm, self.Dia)
116
117
118 HRDict['face'] = 'HR'
119 ARDict['face'] = 'AR'
120 SideDict['face'] = 'Side'
121
122
123 hitFaces = filter(lambda dic: dic['isHit'], [HRDict, ARDict, SideDict])
124
125 if len(hitFaces) == 0:
126 return noInterDict
127
128 dist = hitFaces[0]['distance']
129 j=0
130
131 for i in range(len(hitFaces)):
132 if hitFaces[i]['distance'] < dist:
133 dist = hitFaces[i]['distance']
134 j=i
135
136 return {'isHit': True,
137 'intersection point': hitFaces[j]['intersection point'],
138 'face': hitFaces[j]['face'],
139 'distance': hitFaces[j]['distance']
140 }
141
142 - def hit(self, beam, order, threshold):
143 '''Compute the refracted and reflected beams after interaction.
144
145 BeamDumps always stop beams.
146
147 beam: incident beam. [GaussianBeam]
148 order: maximum strayness of daughter beams, which are not returned if
149 their strayness is over this order. [integer]
150 threshold: idem for the power of the daughter beams. [float]
151
152 Returns a dictionary of beams with keys:
153 't': None
154 'r': None
155
156 '''
157
158 dic = self.isHit(beam)
159 beam.Length = dic['distance']
160 beam.OptDist = beam.N * beam.Length
161 if settings.info:
162 print "theia: Info: Reached beam stop (%s on %s)." \
163 %(beam.Ref, self.Ref)
164
165 return {'r': None, 't': None}
166