Speaker
Description
Summary
The LHCb Muon system consists of five stations of detectors, M1 to M5, only the
first one lying before the calorimeters. Each station is radially segmented in
logical pads, which are the input cells to the level-0 Muon trigger, of four sizes,
R1 to R4.
Most of the system is builts with the wire-chamber technology while only M1-R1 is
built with the triple-GEM technology.
The front-end electronics of the Muon detector is based on two custom chips: the
CARIOCA (with a modified version for the GEM detector)and the DIALOG, both
designed with the 0.25mm radiation tolerant technology.
The CARIOCA is a fast (about 10ns peaking time) and low-noise (ENC=2500e-+45e-
*Cdet, where Cdet is the detector capacitance in pF, ranging from 15pF to 200pF in
the Muon system) amplifier-shaper-discriminator chip, with an active baseline
restoration circuit. A special version of it, named CARIOCA-GEM, was designed in
order to read-out the triple-GEM detector, with a modified shaping stage not
including the ion tail cancellation circuit.
The DIALOG chips takes care of the logical channel generation for the trigger and
of the interaction with the slow control system, i.e. threshold setting and front-
end monitoring.
The front-end boards house two CARIOCA chips and one DIALOG chips.
The experiment is now in the production phase of the front-end electronics,
including 8,000 boards and the 24,000 chips.
The front-end chips and boards are being extensively tested in the lab and their
interaction with grounding issues and power supply distribution of the chambers
studied in detail.
