[en] This paper describes the construction of a silicon tracker built to investigate how well silicon detectors can predict the position of particles in nuclear emulsions over a large area. The tracker consists of 72 single-sided silicon microstrip detectors with a total surface of 0.13 m² distributed over four layers, providing two x and two y coordinate measurements. The set-up was installed in a CERN PS pion beam in September 1997. (author)

[en] A system is described which parallelizes the readout of the existing CERN RMH system and allows fast processing of MWPC data by distributing the hit wire information to an array of Transputers. Two new Transputer based modules were developed for the use in the implementation of a programmable second level track finding trigger for the UA6 experiment at the CERN Spanti pS. (orig.)

[en] The NOMAD trigger system is described in the present paper. It is made up of a large area plastic scintillator veto system, two trigger scintillator planes inside a 0.4 T magnetic field and their associated trigger electronics. Special features of the system consist of the use of proximity mesh photomultipliers which allow the trigger scintillators to operate in the magnetic field, and the use of custom-built VME modules which perform the trigger logic decisions, the signal synchronisation and gate generation, event counting and livetime calculations. This paper also includes a description of each of the NOMAD triggers, with their calculated and measured rates, efficiencies and livetimes

[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