Speaker
Description
Summary
The LHCb Silicon Tracker is part of the LHCb main tracking system and provides data
for region of high track densities. For the tracking station TT in front of the main
dipole magnet, the Silicon Tracker covers the full acceptance angle of the
experiment, while for the stations T1-T3 after the magnet, the Silicon Tracker only
covers the region directly around the beam pipe. The analogue hit information of the
silicon strip detectors, which is amplified by the Beetle readout chip, is
transmitted via copper cables to the Services Boxes, which are located outside the
acceptance area. This does not only reduce the amount of material inside the
detector but in addition relaxes the requirements to the Service Box electronics
concerning radiation tolerance. The Service Boxes hold the Digitizer Boards, on
which the analogue signals from the Beetle frontend chips is digitized and encoded
into a Gigabit data stream for transmission via VCSEL diodes and 120 m of multi-
ribbon optical fibre to the counting house. In the counting house, the optical
ribbons can be directly connected to TELL1 preprocessor boards equipped with two
multi-channel optical receiver cards.
This talk briefly describes the general design of the Silicon Tracker readout system
and its common elements with other LHCb subdetectors. We present results on
performance and lessons learned from the production of preseries modules, which have
been included in the final design. The full production of 700 units will be done
this summer and details about production lot testing and burn-in are given. The
final design was also tested again for radiation tolerance by a proton irradiation,
of which results will be shown. Preseries modules have been connected to a full
length setup of the readout link with optical ribbon cable. On the receiving side,
a first preseries unit of the common LHCb Level-1 preprocessor board (TELL1) was
used to record the data coming from a beetle readout hybrid. For trigger control, a
LHCb TFC readout supervisor was used together with the optical TTC trigger
distribution network, therefore representing the first global setup using LHCb DAQ
components.
