[en] In this paper we describe the low noise electronic amplification chain designed for the readout of the one-stage vacuum photomultipliers (phototriodes) of the DELPHI lead-glass calorimeter. A mean open input electronic noise of 166 e^- rms has been obtained with unipolar shaping. For completely mounted phototriodes in a situation very close to the final experimental setup and bipolar shaping we get a mean noise of 292 e^- rms. Very good immunity against acoustic noise has been obtained. The gain stability during six months of operation is better than ±0.3%. (orig.)

[en] We present an overview of the data acquisition system (DAQ) and event building of OPERA. OPERA is a long baseline neutrino experiment with a high modularity detector and low event rate. To deal with these features a distributed DAQ system base on Ethernet standards for the data transfer has been chosen. A distributed GPS clock signal is used for synchronizations and time stamp of the data. This architecture allows very modular and flexible event building based on a software trigger strategy. We also present its specific application to the spectrometer sub-detector where RPC trackers are installed. Self-triggerability is a dedicated feature to be also sensitive to out-of-spill events and to possibly allow data taking before the official start of the experiment

[en] This paper describes the characteristics of a 32-channel amplifier which, used together with a standard amplifier for MWPCs, gives good quality amplification chain for the signals of a proportional inclined chamber (PIC). The signal amplification must be of high quality to ensure high resolution in the drift time measurement. (orig.)

[en] This note describes the performance of modules assembled with up to 12 silicon microstrip detectors. These modules were built for the instrumented Silicon Target (STAR) that has been installed in the NOMAD spectrometer. Laboratory and test beam results are compared with model predictions. For a module of nine detectors, test beam results indicate a signal-to-noise ratio of 19, a hit finding efficiency of 99.8% and a spatial resolution of 6.0 μm. Laboratory measurements indicate that modules of twelve detectors exhibit a signal-to-noise ratio of the order of 16. (orig.)

[en] The NOMAD-STAR detector is a silicon vertex detector installed in the NOMAD spectrometer at the CERN SPS neutrino beam. It consists of four layers of a passive boron carbide target with a total mass of 45 kg and five layers of 600 single-sided silicon microstrip detectors covering a total area of 1.14 m². About 11,500ν_μ charged current interactions were reconstructed in the fiducial volume of NOMAD-STAR from the neutrino run in 1998. The potential use of silicon detectors for ν_μ(ν_e)↔ν_τ oscillations depends on the observation of the τ candidates by the experimental signature of a large impact parameter, in the case of the one prong decay of the τ, or a double vertex, in the case of the three prong decay. The main aim of NOMAD-STAR is to measure the impact parameter and vertex distributions of charged current interactions, which constitute the main backgrounds for the oscillation signals, to understand the significance of a potential signal in a future experiment. The present paper describes the experience gained in the operation of this silicon vertex detector, and the performance achieved with it

[en] Results are presented from a test in the CERN SPS North Area of a prototype of the DELPHI microvertex detector. Full-sized modules built up from prototype ac-coupled detectors and VLSI readout electronics were used. The spatial resolution of the detectors equipped with prototype VLSI chips was measured to be 6.5 μm. The system aspects, including the readout, were found to work well. Extrapolating to the final components we expect to achieve a measurement precision of 5 μm with the DELPHI microvertex detector. (orig.)

[en] A description is given of the NOMAD electromagnetic calorimeter, consisting of 875 lead-glass counters read out by two-stage photomultipliers and a low noise electronic chain. The detector operates in a 0.4 T magnetic field transverse to the counter axis. The paper discusses the design criteria, the lead-glass characteristics, the properties of the read out chain and provides a summary of the calorimeter performance. (orig.)

[en] The document describes the front-end electronics that instrument the spectrometer of the OPERA experiment. The spectrometer is made of two separate modules. Each module consists of 22 RPC planes equipped with horizontal and vertical strips readout for a total amount of about 25,000 digital channels. The front end electronics is self-triggered and has single plane readout capability. It is made of three different stages: the Front End Boards (FEBs) system, the Controller Boards (CBs) system and the Timing Boards (TBs) system. The FEB system provides discrimination of the strip incoming signals; a FAST OR output of the input signals is also available for trigger plane signal generation. FEBs discriminated signals are acquired by the CBs system that manages also the communication to the experiment DAQ and Slow Control interface. A Trigger Board allows to operate in both self-trigger (the FEB FAST OR signal starts the plane acquisition) or external-trigger (different conditions can be set on the OR signals generated from different planes) modes

[en] OPERA is one of the two detectors foreseen in the CERN Neutrino to Gran Sasso project, devoted to the detection of νμ into ντ oscillations in the parameter region suggested by SuperKamiokande data on atmospheric neutrinos. Bakelite RPCs will be used to instrument the iron yoke of the muon spectrometers. We present the results of long-term (greater than 6 months) streamer operations of real size OPERA RPCs at cosmic rays fluxes. Given the very low rate observed in the underground Gran Sasso Laboratories, under 3km w.e., even this short time period is equivalent to more than 10 OPERA years. Results of tests with different gas mixtures are reported, in view of decreasing the streamer charge of operation for the RPCs employed in the experiment

[en] The construction and performance of a large area scintillator-based time-of-flight detector for the HARP experiment at CERN are reported. An intrinsic counter time resolution of ∼160 ps was achieved. The precision on the time calibration and monitoring of the detector was maintained at better than 100 ps by using dedicated cosmic rays runs, a fast laser-based system and calibrations with beam particles. The detector was operated on the T9 PS beamline during 2001 and 2002. A time-of-flight resolution of ∼200 ps was obtained, providing π/p discrimination at more than 3σ up to 4.0 GeV/c momentum