To calibrate the energy response of the ATLAS liquid argon calorimeter, an electronics calibration board has been designed; it delivers a signal whose shape is close to the calorimeter ionization current signal with amplitude up to 100mA in 50Ω with 16bit dynamic range. The amplitude of this signal is designed to be uniform over all calorimeters channels, stable in time and with an integral linearity much better that the electronics readout. The various R&D phases and most of the difficulties met are discussed and illustrated by many measurements. The custom design circuits are described and the layout of the ATLAS calibration board presented. The procedure used to qualify the boards is explained and the performance obtained illustrated: a dynamic range up to 3TeV in three energy scales with an integral linearity better than 0.1% in each of them, a response uniformity better than 0.2% and a stability better than 0.1%. The performance of the board is well within the ATLAS requirements. Finally, in situ measurements done on the ATLAS calorimeter are shown to validate these performances.
The ATLAS detector has been designed for operation at CERN's Large Hadron Collider. ATLAS includes a complex system of liquid argon calorimeters. The electronics for amplifying, shaping, sampling, pipelining, and digitizing the calorimeter signals is implemented on the Front End Boards (FEBs). This paper describes the design, implementation and production of the FEBs and presents measurement results from testing performed at several stages during the production process.
The construction and assembly of the two half barrels of the ATLAS central electromagnetic calorimeter and their insertion into the barrel cryostat are described. The results of the qualification tests of the calorimeter before installation in the LHC ATLAS pit are given.
The development of the NEMO3 detector, which is now running in the Frejus Underground Laboratory (L.S.M. Laboratoire Souterrain de Modane), was begun more than ten years ago. The NEMO3 detector uses a tracking-calorimeter technique in order to investigate double beta decay processes for several isotopes. The technical description of the detector is followed by the presentation of its performance.
The ATLAS collaboration has chosen for the electromagnetic barrel calorimeter and for all the end-cap calorimeters a sampling technique, with liquid argon as the active medium. The read-out electronics and the calibration pulsers are located in boxes outside the cryostats housing the detectors. Signals are transmitted between the detectors and the electronic boxes through custom-designed micro-coaxial cables, which are the subject of this paper. These cables have to satisfy very stringent tolerances in terms of signal transmission, dimensions and radiation hardness. Following a successful pre-series production, these cables have been selected for equipping the ATLAS calorimeter.
Recent results from the front-end electronics of the Detector of Internally Reflected Cerenkov light (DIRC) for the BaBar experiment at SLAC (Stanford, USA) are presented. It measures to better than 1 ns the arrival time of Cerenkov photoelectrons, detected in a 11,000 phototubes array and their amplitude spectra. It mainly comprises 64-channel DIRC front-end boards (DFB) equipped with eight full-custom analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom digital TDC chips for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC crate controller cards (DCC) serializing the data collected from up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test results of the pre-production chips are presented, as well as system tests.