[en] For the first time the (nbarp) system has been investigated in detail by using the unique nbar beam facility of the OBELIX experiment at LEAR. The advantages and usefulness of nbar beams, as complementary to the pbar ones, for studying the NbarN annihilations are discussed. After describing the nbar production techniques the most relevant results achieved during the last five years, on annihilation dynamics, meson spectroscopy and annihilation on nuclei are reported. The possibility to continue such a line of research in future at JHF is put forward

[en] The FINUDA experiment is ready to start physics at the DAΦNEφ factory in Frascati. There the Κ^- of low energy can be used to produce Λ-hypernuclei through the Κ_stop^- + ^AZ → _Λ^AZ + π^- reaction. The FINUDA apparatus has been designed to reach high moment resolution (0.3%) and acceptance (2π sr) for the π^- coming from hypernucleus formation, moreover it has excellent detection capability for the products coming from hypernucleus decay. Therefore it is possible to perform high statistics measurements, either on high resolution spectroscopy, either on hypernucleus decay modes. Expected performances and physics programme are here summarised. (author)

[en] The advantages and usefulness of n-bar beams, as complementary to the p-bar ones, for studying the N-bar N annihilations are shown to be sound. After describing the n-bar production techniques the most relevant results so far achieved are reported. The possibility to continue such a line of research in the near future at JHF is put forward. (author)

[en] Results of measurements of the performances of a prototype of a time-of-flight scintillator hodoscope suited for neutron detection are described. The hodoscope will have a configuration that allows the use of a reduced number of photomultipliers. The scheme was already used for the detection of charged particles and the measurements show that the good performances are maintained even with the continuous pulse height spectra produced by neutrons

[en] We developed an electronic system which, used with drift chambers, allows to perform a precise charge division measurement of the longitudinal coordinate, even if the sense wire is held at high voltage and a decoupling capacitor is needed. The idea is to create a temporal gate at the arrival of the signal and transmit to the ADC only this part of the signal. The gate remains open for a short period (120 ns), corresponding to the duration of the anode pulse and delivers, at its output, a pulse of amplitude linearly dependent from the input value. In this way the systematic error is better than 1% of the wire length. It introduces a considerable improvement in comparison with previously used software corrections, mainly from the linearity and simplicity point of view

[en] This paper reports on Songa, which is a detector for underground water circulation studies with radioactive tracers. The interest and the curiosity of studying with radioactives tracers an underground water circulation network in the Sardinia Island led us to develop a low-level large volume detector for measuring in real time the gamma-radioactivity in water. The detector is made of plastic scintillator interleaved with Pb converters. The system is able to operate plunged underwater up to 30 m and has a sensitivity level of 10^-3 Bq/ml

[en] Results of measurements of the performances of a time-of-flight neutron hodoscope consisting of 50 slabs of plastic scintillator, 100 x 2 x 5 cm³ each, are described. The efficiency and the spatial localization properties along a slab were studied with a variable energy (2.4 to 16.4 MeV) neutron beam. The hodoscope was finally used in the experiment PS 178 at the LEAR facility at CERN. The use of large area scintillator hodoscopes for neutrons, giving the time-of-flight (TOF) and the impact position, is becoming more and more frequent in experiments on intermediate energy physics. The authors were faced with this problem in designing an apparatus dedicated to the study of antineutron (n) physics at the LEAR facility at CERN

[en] This paper describes the structure of the first level trigger of the OBELIX spectrometer. It is based on a detector made of two coaxial cylinders of scintillators slabs and on the associated electronics. Different trigger options are allowed and any relevant parameters can be set and monitored via software

[en] Antineutron annihilation cross sections on C, Al, Cu, Ag, Sn and Pb targets were measured in the momentum range 50-400 MeV/c. The full set of data is very well described by a parameterization in which the target mass number and momentum dependence are factorized. The A dependence is, within 2%, consistent with a A^2/3 scaling law, indicating a pure surface process. The momentum dependence is, within 20%, consistent with that expected from a properly averaged contribution of the elementary cross section for nbarp and nbarn annihilation, indicating that the process is due to the interaction with single nucleons on the surface

[en] We have developed a simple scheme to reject crosstalk signals in plastic scintillator hodoscopes with an accuracy better than 0.5%. (orig.)