Sep 25 – 29, 2006
Valencia, Spain
Europe/Zurich timezone

Overview of LHCb electronics installation aspects

Sep 26, 2006, 10:55 AM
Valencia, Spain

Valencia, Spain

IFIC – Instituto de Fisica Corpuscular Edificio Institutos de Investgación Apartado de Correos 22085 E-46071 València SPAIN


Vincent Bobillier (CERN)


The infrastructure for the electronics, such as cabling, mains power distribution, low and high voltage power supplies, detector safety system, grounding and its installation in the LHCb experimental cavern will be presented. In particular, choices and compromises that have been made for power distribution, racks, cables and cable ducts installation, grounding (EMC) and optical fiber link tests will be described.


LHCb presents some particularities compared to other LHC experiments due to its
geometry (forward cone coverage). This geometry offers the advantage that most
sub-detectors are constructed in two halves that can be opened for maintenance.
Accessibility to the on-detector electronics is therefore reasonably easy and
equipment such as power supplies can be installed relatively close to front-end
electronics. On the other hand, the fact that sub-detectors can be opened implies
specific constraints for the cabling and the grounding of the sub-detectors.
A 4 meter thick shielding wall made of concrete blocks protects DAQ interface
electronics and a large PC farm of ~2000 computing nodes against radiation. Cabling
from sub-detector specific in/on detector front-end electronics to the protected
counting house has a length of minimum 60 meters. The shielding wall acts as an
important obstacle for all power, readout and control services that have to pass
through a narrow chicane.

The following points are planed to be presented:

  • Overview of LHCb electronics installation
  • Main choices in electronics and electrical installation
    o Choice of LVPS and their position in the pit (magnetic stray field and radiation)
    o Same for HVPS (recommendations)
    o Cabling recommendations (shielding wall constraints, use of patch panels,
    moveable parts / use of shielded cables when possible / closed metallic cable ducts
    for EMC)
    o Mains power distribution and main choices (separation of farm and electronics
    distribution, harmonics, remote control, …)
  • Grounding scheme in the experimental cavern
  • Optical fiber cables
    o Cable type choice (Multi-mode fibers, MPO connectors, multi-ribbon, gain of space,…)
    o Testing and verification of optical fiber links.
  • Racks control and monitoring.
  • DSS (detector safety system).

Primary author


Presentation materials