Overview of the tracking system

 

Vertex Detector (VXD)

Barrel:

• 4 double-layer cylindrical shells at radii  3.0, 5.1, 7.4, 10.2 cm; barrel length = 13.0 cm; double layer gap = 2 mm; 

Endcap: 

• 4 + 4 double-layer disks at |z| = 8.0, 12.0, 20.0, 28.0 cm; double layer gap = 2 mm.

Inner Tracker (IT)

Barrel:

• 3 cylindrical shells  at radii 12.7, 34.0, 55.4 cm; barrel length = 96.32 (layer 0 and 1), 138.46 cm (layer 2);

Endcap:

• 7 + 7 disks at |z| = 52.4, 80.8, 109.3, 137.7, 166.1, 194.6, 219.0 cm.

Outer Tracker (OT)

Barrel:

• 3 cylindrical shells  at radii 81.9, 115.3, 148.6 cm; barrel length = 252.84 cm;

Endcap:

• 4 + 4 disks at |z| = 131.0, 161.7, 188.3, 219.0 cm. 

 

		Cell Size	Sensor Thickness	Time Resolution	Spatial Resolution
Vertex Detector	B	25 μm x 25 μm pixels	50 μm	30 ps	5 μm x 5 μm
	E	25 μm x 25 μm pixels	50 μm	30 ps	5 μm x 5 μm
Inner Tracker	B	50 μm x 1 mm macropixels	100 μm	60 ps	7 μm x 90 μm
	E	50 μm x 1 mm macropixels	100 μm	60 ps	7 μm x 90 μm
Outer Tracker	B	50 μm x 10 mm microstrips	100 μm	60 ps	7 μm x 90 μm
	E	50 μm x 10 mm microstrips	100 μm	60 ps	7 μm x 90 μm

 

Tracker material budget

Hadronic interaction length (left) and radiation length (right) of the tracker for the geometry MuColl_v1:

 

BIB hit occupancy

Average density of BIB hits in the tracker layers per bunch-crossing (left) and polar angle distribution of the BIB hits (right) for one bunch-crossing:

Tracking performance plots