[en] A gateless charge integrator designed for the energy measurement in the Borexino experiment is described and the results of various tests performed on prototypes are shown. The circuit integrates always its input taking advantage of the AC coupling to the photomultipliers that equalizes to zero the charge associated with each event signal. A double sampling of the integrator output allows to perform a charge measurement in principle without dead time, avoiding the use of gate signals and baseline restoration networks and permitting a precise detection of the fast correlated events (delayed coincidences due to the decay of a nuclide producing a daughter having a lifetime in the tens of ns time range). The precision of the charge measurement is discussed together with the performances of the front end Borexino board where the integrator is mounted

[en] The authors have built a 5-cell superconducting structure, for the main section (β=1) of an e^- linear accelerator, forming half cavities, ''door-bell'' shaped, by deep drawing a 2 mm thick niobium sheet. Running the structure in the π mode, (the accelerating one) accelerating field in excess of 7 MV/m was achieved at a fairly low Q /SUB o/ value of 3x10⁸. The authors report a comparison between the results obtained in a single cell cavity of the same shape (B /SUB p/ about 50 mT) and that ones previously obtained in the 1 mm thick cavities operating at the same frequency (B /SUB p/ = 105 mT). They introduce a simple model for the heat transfer to He bath which explain the worse behaviour of the low Q /SUB o/ cavities

[en] This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

[en] The production, by means of a single hexapolar magnet, of an atomic hydrogen beam with velocity resolution (FWHM) of about 10%, suitable for scattering experiments at thermal energies, is described

[en] This chapter discusses the feasibility and the experimental possibilities of a technique for trapping and cooling at very low energy (of the order of a few Kelvin) antiprotons or antideuterons in a Penning trap. Topics covered include storage trap design and cooling, the Penning trap, maximum density of the stored particles, the lifetime of the stored antiprotons, the principle of the measurement, the principle source of errors, and other possible uses for the stored antiprotons. The performances of a Penning trap for trapping and storing antiproton bunches injected from the Low-Energy Antiproton Ring (LEAR) or from some of the newly proposed devices are analyzed. The properties of the Penning trap as a mass spectrometer for measuring the ratio m /SUB p/ /m /SUB p/ are discussed. Some other measurements on the trapped ^-p's are suggested

[en] In this document, we present the design and the implementation of the electronic system for the Borexino experiment, which is devoted to the measurement of the ⁷Be solar neutrino flux. The system is directly connected to the detector photomultipliers (PMT): for each of these the arrival time and the collected charge for the single light pulse is measured. The complete system is composed of the following: a front-end stage, which performs an analog processing of the PMT signal; a readout stage, used to digitize and store the signal processed by the front end and to measure the arrival time and the charge of each light pulse coming from the detector; a trigger stage, used to identify interesting events. In the following, a detailed description of each of the preceding stages is given

[en] The KfK open-quote Cyclotron trap close-quote has been modified to act as a deceleration and trapping device for a large number of antiprotons. An active injection device (kicker) and a pair of pulsed extraction electrodes have been placed in the cyclotron chamber. A cylindrical e.m. trap has been added in the axial bore of the cyclotron magnet and a separation membrane has been inserted to decouple the cyclotron chamber from the high-vacuum region of the trap. The authors report here preliminary results of a test of this apparatus, performed at the LEAR 72 MeV/c antiproton beam. 5 refs., 7 figs

[en] Preliminary results about the handling of charged plasma in ATHENA are shown describing both the destructive and the non-destructive methods

[en] A method for measuring the Earth's gravitational acceleration g on antiprotons is proposed. The value of g is obtained by measuring the gravity-induced shift of the center of the radial orbits of antiprotons that are stored in a Penning trap. Such a shift is a measurable effect for particles of very low energy (congruent 1 μeV) if the point of injection lies near the axis of a big Penning trap in which the magnetic field is perpendicular to the direction of g. A possible experimental setup is described and several sources of error are analyzed. A comparison with a time-of-flight method, originally proposed to measure g on antiprotons (and now under experimental investigation by an international collaboration), indicates the advantages of the present proposal. The experimental feasibility of the method of measurement that we propose relies on the practical limit that can be achieved in minimizing the antiprotons' energy and on controlling the radial coordinates of the particles before injection into the g-sensitive trap

[en] The AEgIS experiment (http://aegis.web.cern.chhttp://aegis.web.cern.ch) will measure the gravitational acceleration g of antihydrogen. Once performed this could be the first direct test of the gravitational interaction between matter and antimatter. In the AEgIS experiment a beam of antihydrogen will travel horizontally along a path of about 1 m trough a moiré deflectometer followed by a position sensitive detector. The g value will be obtained measuring the vertical displacement of the annihilation patterns. Before producing the beam, several tasks have to be performed mainly involving positron and electron plasma manipulation and particles cooling in Malmberg-Penning traps. The AEgIS experiment is currently under construction at CERN, meanwhile several tests involving particle manipulation and particle cooling are in progress. In this report some experimental results involving diocotron manipulation of plasma will be presented.