[en] The maintenance of a particle detector functionally requires the knowledge of more experts: physicists for the detectors, engineers for the electronic. The integration of different knowledge and experiences can be done using an Expert System. A real-time Expert System, based on the NEXPERT commercial tool, allows the diagnosis of the detector and data acquisition system anomalies. It performs an on-line diagnosis and, if an abnormal condition is identified, takes the appropriate action to reduce the unavailability of the apparatus. The data acquisition system is Camac based and the sensor modules, that gather the significant values for diagnosis, are implemented in the VME crate

[en] A connection between a microVAX and a VME crate has been realized using two links: one is capable of DMA transfer and the other in Qbus I/O mapped. An effective rate higher than 0.5 Mbytes/s has been obtained transferring large data blocks with the DMA interface, while a rate of about 0.3 Mbytes/s has been reached with the I/O-mapped method. (orig.)

[en] MACRO is a large area detector designed to search for rare phenomena in the cosmic radiation (GUT monopoles or supermassive charged penetrating particles), to study the penetrating cosmic ray muons, to detect neutrino bursts originated by gravitational stellar collapses in the galaxy and to perform a survey of cosmic point sources of high energy neutrinos. The detector, located at a depth of about 3,600 meters of water equivalent in the INFN Gran Sasso Laboratory (LNGS), has an acceptance of about 10,000 m²sr for an isotropic flux of particles. It consists of plastic streamer tubes, liquid scintillation counters and track-etch detectors arranged in a modular structure, the basic element called ''supermodule'' having dimensions 12 x 12 x 5 m³. Presently 6 supermodules are operative and have been taking data since June 1991. Here an acquisition system based on a network (Ethernet/DECNET) of KAV30 VAX processors is described. KAV30 is a VME single board computer based around rt-Vax 300 and running in VAXELN, a Digital Equipment software product for the development of dedicated, real time systems for VAX processors. A central VAX running under the VAX/VMS operating system is used as file server and as an interface of the acquisition system with respect to the user's world

[en] The authors describe an acquisition system based on a network (Ethernet/DECNET) of MicroVAX's running in the VAXELN environment. VAXELN is a Digital Equipment software product for the development of dedicated, real time systems for VAX processors. A central VAX running under the VAX/VMS operating system is used as file server and as an interface of the acquisition system with respect to the user's world

[en] This paper describes the manufacture of multicell plastic limited streamer chambers for use in the hadron calorimeter of the OPAL detector at LEP. The chambers are of the PVC coverless type with highly resistive cathodes. We discuss the assembly procedure with particular emphasis on the crucial cathode preparation process. A summary of test results is also presented. (orig.)

[en] A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6x10^-15 cm^-2 sr^-1 s^-1 at 90% confidence level in the velocity range of 10^-4 approx-lt β<4x10^-3. This result places a new constraint on the abundance of monopoles trapped in our solar system

[en] We report on the simultaneous observation of atmospheric Cerenkov light by a prototype five telescope array, GRACE, (Gran Sasso Air Cerenkov Experiment) with deep underground muons in the MACRO (Monopole Astrophysics and Cosmic Ray Observatory). The telescope array was deployed at Campo Imperatore above the Gran Sasso Laboratory for a run completed in the fall of 1992. The total live time for the combined surface-underground operation was ∼100 h during which more than 300 events were seen in coincidence. The efficacy of this technique to monitor the electromagnetic and penetrating muon components of a cosmic-ray-induced cascade is discussed

[en] The MACRO detector is presently under construction, its installation at Gran Sasso being planned to start in September 1987. It is a large area detector, the acceptance for isotropic particle fluxes being around 10 000 m² sr, designed to search for rare phenomena in the cosmic radiation. It makes use of three detection techniques: liquid scintillator counters, plastic streamer tubes, and track-etch. It will perform a search for GUT monopoles (or any supermassive charged penetrating particle), a survey of cosmic point sources of HE gammas and neutrinos, a systematic study of the penetrating cosmic ray muons, and will be sensitive to neutrino bursts from gravitational stellar collapses in the Galaxy. (orig.)

[en] The half of the MACRO detector, a large area Monopole, Astrophysics, Cosmic Ray Observatory is nearly completed in Hall B of the Gran Sasso Laboratory. One supermodule is already taken data and the remainder will be activated in few months. A general overview of the MACRO detector, together with it's physics capabilities as far as the search for point sources of high energy neutrino is concerned, will be presented. (orig.)