The LUCID detector

LUCID is located inside the support cone of the VJ beam pipe

The only access is through small holes

16+16 tubes with PMT

4+4 tubes with fibers

LUCID Performances in 2010 (1)• The agreement between data and Monte Carlo was much

better than what was expected from the 450 GeV run.• The background was low.• The calibration was limited by the uncertainty in the beam

current measurements and not by detector effects.• LUCID was the only detector that provided a precise and

stable luminosity measurement during all of 2010.

Conclusion: the LUCID running in 2010 was a great success !

LUCID Performances in 2010 (2)• Most analysis in ATLAS are using LUCID luminosity data (3.4 %

error) either for measurements or for normalization of Monte Carlo simulations

INFN Bologna contribution• LUCID has proven to be a stable and well performing luminosity monitor

for ATLAS• It has been designed built and commissioned using almost completely

INFN Bologna section resources– Detector mechanics project and realization– Full electronics system (PMT and fiber readout): development of Fibers readout front

end,PMT front end, backend, CFD, led calibration, pulser calibration, lumat card

PMT

Fibers

Fibers

Electronics

HV distribution box

Nowadays, the particle physics experiment are technologically very advanced and CAN NOTbe build without a proper technical support.The Bologna INFN section provides since many years an impeccable services to itsresearchers activities. Some examples of this are given in this and the following slides.

• Lucid Mechanics Design developed by Bologna

(G. Laurenti e S. Michinelli)• Workshop Resp.: M . Guerzoni

LUCID Electronics CardPulser Calibration System Pulser +LED Calibration System

As installed in ATLAS

OLD and NEW Analog signals receiving cards

• Fully designed and developed in Bologna (G. Avoni)

• Electronics Lab resp: I. D’Antone

LED CALIBRATION DATA

~ 15 ns

~ 15 mV

SINGLE PHOTOELECTRONSIGNAL AFTER ~100 m CABLELUCID READOUT CAN FOLLOW THE BUNCH!

, Typical 1 track signal ~ 100 pe

1 photo electron (pe) peak

1

0

3QSN

The CFD card

• Transforms analog signals in hits and provides integrated on-line luminosity

• Fully designed and developed in Bologna (S. Meneghini)

Alternative scheme for LUCID Readout

9

LUMAT CARD

•4 tubes in each detector are read-out by quartz fibers•The data recorded with this system should be able to tell us if the fiber readout is a viable option for possible future developments •Fully designed and developed in Bologna (C. Baldanza)

PLACED ON THE TOPOF TX1S

Accessory Electronics Modules

• Designed and developed by Bologna (G. Avoni)

Digital Delay Line

TTL to diff ECL/LVDS translator

Lumat CARD

• The LUMAT CARD is providing the ATLAS ON-LINE Luminosity (By BUNCH and INTEGRATED)

• Designed and developed in Bologna (M. Villa, G. Avoni, G.Pellegrini)

Mezzanine Card(re-using the CMS barrel sorter mezzanine)