[en] Three synchrotron radiation beam lines have been built on DAΦNE, the Frascati electron-positron accelerator. It is possible to monitor and control all the elements on the beam lines using a modular network distributed I/O system by National Instruments (FieldPoint) with Bridge VIEW/LabVIEW programs. Two of these beam lines have radiation safety problems solved by two independent and redundant systems, using mechanical switches, and S7-200 PLC's by Siemens. The authors' solution will be described in details

[en] Resistive Plate Chambers (RPCs) are widely used in high energy physics. While avalanche mode operation is mandatory in high rate environments (ATLAS and CMS experiments at LHC), streamer mode operation is often preferred in low rate applications because of the high signal amplitude. Typical mixtures for streamer operation are composed of Argon, Tetrafluoroethane and Isobutane, with additions of SF₆ below 1% to reduce the charge delivered in the gas. In this paper, results about the streamer properties observed with different mixtures are presented.

[en] OPERA is a dedicated experiment for the observation of ν_μ into ν_τ oscillations through τ appearance using a 730 km long baseline ν_μ beam from CERN to the Gran Sasso underground laboratory. The detector is equipped with two spectrometers for muon identification and charm background rejection. Bakelite RPCs are used as inner trackers inside the iron magnet of the spectrometers. The experiment has already performed two short runs in 2006 and 2007. Results about the RPC performances are presented.

[en] The OPERA experiment is designed to study the ν_μ→ν_τ oscillation observing the ν_τ appearance in a pure ν_μ beam over a base line of 732 km from CERN to Gran Sasso Laboratory. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors and muon spectrometers for muon charge and momentum measurements. The tracking inside the magnets is provide by Bakelite RPC chambers in a large scale application. The commissioning of the RPC system ended in August 2006. The paper present the layout of the RPC system and its performances.

[en] OPERA is an experiment dedicated to the observation of ν_μ into ν_τ oscillations through τ appearance exploiting the CNGS beam. The experiment is composed by two identical super-modules, each with a target section (made of emulsion/lead bricks alternated with a scintillator Target Tracker) and a muon spectrometer (instrumented with bakelite RPCs and drift tubes). The RPCs are operated in streamer mode with the gas mixture Ar/C₂H₂F₄/isoC₄H₁₀/SF₆=75.4/20/4/0.6. The present performances of the RPC detectors are presented and the aging status of the system after four years of operation is described. The sample of events induced by the CNGS neutrino beam as well as a large sample of cosmic rays have also been used to study general properties of streamer-operated RPCs.

[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