Central tracker
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Three doublets of silicon drift detector
sigma_rphi = 10 microns, sigma_rz = 20 microns
Radii: (active)
r1 = 14 cm r3 = 42 cm
r5 = 71 cm
r2 = 15 cm r4 = 43 cm
r6 = 72 cm
Half-lengths: (active)
z1 = 31 cm z3 = 89 cm
z5 = 149 cm
z2 = 31 cm z4 = 89 cm
z6 = 149 cm
Radiation length / layer = 1.2 %
Endcap tracker
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Five disks (nearly) uniformly spaced in z
(covering cos(theta) 0.9 to 0.99)
Inner radii Outer radii
Z position
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4.4 cm 14.5
cm 31.2 cm
8.7 cm 29.1
cm 61.2 cm
13.0 cm 44.2
cm 91.2 cm
17.3 cm 58.1
cm 121.2 cm
21.0 cm 72.5
cm 149.2 cm
Radiation length / layer = 1.2 %
B = 6.0 T
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Vertex detector
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5 layers uniformly spaced from rmin = 1.2 cm to rmax = 6.0 cm
Each layer's half-length is 2.1 times its radius
sigma_rphi = sigma_rz = 5 microns
Inactive
material
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Beam pipe at r = 1.0 cm, thickness = 0.4% X_0
Vdet cryostat at rmin = 7.0 cm, thickness = 0.7% X_0