LHCb Inner Tracker Poster

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The LHCb Inner Tracker
LHCb is a single-arm forward spectrometer
dedicated to B-physics acceptance
15-300(250)mrad

• The Challenges
• Unlike vertex detectors we have
• moderate spatial resolution requirement
  (60mm)
• moderate radiation environment. After 10 years
• 1 Mrad or 91012cm-2 of 1 MeV Neutron equiv. in
  IT
• But we need to cover a large detector area
• minimize R/O channels ? large pitch O(200mm)
• (limits charge
  collection)
• ? long strips 22cm
  (?noise)
• 40MHz, fast readout ? (?noise)
• minimize material ? thin sensors
• (limits amount of
  charge)

The LHCb Inner Tracker covers the high particle
density region near the beam pipe and the bending
plane of the magnet in the tracking stations
behind the magnet with Silicon Strip detectors.
The total area of Silicon is 4.3m2
The Outer Tracker covers the large surface area
with straw tube detectors

• The Inner Tracker Layout
• The Inner Tracker consists of
• 4 individual boxes per station
• 4 layers per station (2 stereo layers)
• ?336 modules 11 and 22cm long
• 129k readout channels on 4.3m2 silicon

• The Inner Tracker
• silicon strip detectors
• 1.3 of the acceptance
• 20 of the tracks

The Inner Tracker Silicon Module
cooling balcony for mounting and positioning
of the ladder on the supporting cooling rod which
is connected to the liquid cooling system
Carbon Fibre (CF) support produced out of high
thermal conductive fibre used to cool the sensors
and the detector box

• Sensors
• Kapton
• Carbon Fibre
• AIREX faom
• Carbon Fibre

• operation at 5C
• liquid C6F14 cooling system for cooling readout
  hybrid and sensors
• thermally conductive CF support
• box enclosure lightweight isolation foam Al
  foil for electrical shielding
• the analog signals from the readout hybrids are
  sent via 5m copper cables to the service boxes
  outside of the acceptance where they are digitised

readout hybrid with 3 Beetle chips in 0.25mm CMOS
technology operating at 40MHz. The 128 channel
front-end signals are pipelined for 160 bunch
crossings. The output data are multiplexed on 4
readout ports allowing for a readout in 900ns
after a trigger.
p-n silicon micro-strip Hamamatsu sensors 384 AC
coupled readout strips 108 mm long strips, 197mm
pitch, w/p0.25 320(410)mm thickness
The Inner and Outer Tracker Support The Inner and
Outer Trackers have individual rail systems on a
common support structure. This allows individual
access to both sub-detectors and their
electronics
Outer Tracker
Inner Tracker box
rail system

Production of Inner Tracker Modules
sensors are positioned according to their edges
on a special jig, picked up by a vacuum tool and
placed on the CF-support, where glue is applied
using a glue dispenser
the readout hybrid is glued together with the
pitch-adapter to the CF-support
bonding machine used to make the electrical
connection between readout hybrid, pitch-adapter
and sensors
CF support bars
Service boxes where the analog signals from the
readout chip are digitised and then optically
transmitted to the counting house where they are
further processed ? TELL1