[en] Limited streamer chambers are extensively used for high-energy and nuclear physics experiments in accelerator and underground laboratories. The tracking system of LVD, an underground experiment to study muons and nutrino astronomy, will use roughly 15000 limited streamer chambers and 100000 external pickup strips with digital readout electronics. In the article the different aspects of chamber operation that serve to establish a testing procedure and to define acceptance criteria for selecting reliable and long-life devices, are discussed. The procedures and the results obtained from a long-term test to evaluate streamer chamber quality, based upon a sample of 2900 items, are described. The selection tests and the long-term observations have been performed in the ASTRA laboratory, established at the Laboratori Nazionali di Frascati to carry out quality control procedures for streamer chambers on a large scale and in a controlled environment

[en] The simulated performances of a non-homogeneous e.m. calorimeter based on a 5 X tracking section using CsI(Tl) fibres, followed by a 10 X₀Pb-SCIFI head-on back section are reported. The study shows that such a technique is quite promising for the high-efficiency detection of photons in the energy range of interest at a φ-factory machine

[en] We report on the simulated performances of a non-homogeneous e.m. calorimeter based on a 5X₀ tracking section using CsI(Tl) fibres, followed by a 10X₀ Pb-SCIFI head-on back section. Our study shows that such a technique is quite promising for the high-efficiency detection of photons in the energy range of interest at a Φ-factory machine. (orig.)

[en] In order to perform an indoor survey of internal exposure to radon and its short life daughters using track etching passive detectors, it is necessary to analyze a large amount of information without spending a lot of time and manual work. For this purpose, the possibility of utilizing PEPR (Precision Encoding and Pattern Recognition) normally used in the digitization of low energy particle tracks recorded on Bubble Chamber film has been studied. A special subroutine has been set up for a PDP 11/45 Computer to guide PEPR in studying the tracks of α-particles in CR39. (author)

[en] This article reports on studies aimed to characterise the properties of plastic scintillating fibres to be used in head-on, 1:1 Pb-SCIFI calorimetric modules. The effect of glue on the attenuation of the light transported by cladding close to the photomultiplier tube is studied and found to effectively decrease the contribution of cladding light. Pb-SCIFI modules have been assembled and tested on a 20-80 MeV tagged photon beam. Good linearity and energy resolution better than 6%/√E[GeV] were achieved, therefore showing that this technique is suitable for experimentation at φ-factories. (orig.)

[en] The Precision Encoding and Pattern Recognition was tested in order to analyze radon α-particle tracks in CR39. The system operates on photographic films of the tracks, measuring optical densities. Three different algorithms of acquisition and measurement of the tracks were set up. With this technique pieces of CR39 exposed in passive diffusion dosemeters to different radon concentrations were studied. The calibration obtained was compared with that carried out with optical microscope counting. (author)

[en] This article reports on studies aimed to characterise the properties of plastic scintillating fibres to be used in head-on, 1:1 Pb-SCIFI calorimetric modules. The effect of glue on the attenuation of the light transported by cladding close to the photomultiplier tube is studied and found to effectivaly decrease the contribution of cladding light. Pb-SCIFI modules have been assembled and tested on a 20-80 Mev tagged photon beam. Good linearity and energy resolution better than 6%/√E[GeV] were achieved, therefore showing that this technique is suitable for experimental at φ-factories

[en] The LVD detector can be defined as an underground observatory with the main objectives of studying neutrinos from stellar collapse and searching for point-like sources of gammas and neutrinos of very high energy. This multipurpose apparatus is being installed in hall A of the Gran Sasso Laboratory at a vertical depth of 3600 m.w.e. It consists of a large volume of liquid scintillator divided into modules and of a tracking system made of layers of streamer tubes. (orig./HSI)

[en] Expected rates of deep-underground muons in the LVD detector, at a vertical depth of 3600 hg/cm² s.r. (standard rock) at the Gran Sasso, were obtained through Monte Carlo simulation. Two different generators were developed to reproduce single and multiple muon distributions at our detector level. The main purpose was to evaluate the potentiality of the apparatus in studying chemical composition and energy spectra of primary cosmic rays in the range 10¹⁴-10¹⁶ eV through the detection of muon bundles of high multiplicity. Sensitivity of the detector was checked by comparing event-rate predictions for three different models of the primary composition: the Maryland spectrum, the 'low energy composition' model, and the NUSEX parametrization (with spectral index of iron γ_Fe=2.60 and 2.70). We predict a single muon rate in the apparatus of about 3.26x10⁶ events/year. Preliminary results for multiple muon-event detection show that we can separate with a good sensitivity different primary compositions in the multiplicity region around n=10. (orig.)

[en] We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether. (orig.)