[en] The status of the Gargamelle neutrino experiment, in which the elastic reaction νsub(μ)e^- → νsub(μ) e^- has been studied at the CERN SPS energy, is reported and the analysis of the Spring 1978 data is presented. About 160,000 pictures were taken in this period of which 52,000 have been scanned and completely analyzed. One e^- candidate has been found of energy E = 25 +- 11 GeV and thetasub(e) 4 mrad. New methods which are presently under test to separate electrons from γ-rays are discussed. (U.K.)

[en] Results from the Gargamelle experiment on neutrino production of events with muon, electron and V⁰ in the final state are presented together with a complete study of the background. Also given are results of a search for charm decays via hadronic modes. (author)

[en] This report describes a dosimeter based on the conduction calorimetry principle, and designed to operate in swimming-pool type nuclear reactors. The properties of the apparatus are as follows: 1 - the measurement is independent of the specific heat of the calorimetric elements; 2 - each calorimetric element is fitted with an electrical calibration; 3 - the apparatus is made up of two independent calorimetric elements; 4 - the nature of the calorimetric elements makes it possible to analyse the radiation received; 5 - the measurable intensities of the absorbed radiation vary from 4 to 4000 M/rads per hour; 6 - the sensitive part of the apparatus is fitted inside a cylinder 5 cm high and 2 cm in diameter. One pre-production unit made up of graphite and beryllium cores has been tried out in the reactor Siloe with radiation intensities of about 1 to 2 watts per gram. It absorbed an accumulated dose of 1.2*1O¹² rads without any weaknesses appearing. (authors)

[en] The quasi-elastic cross-sections sigmasub(el)sup(tot) and dsigma/dq² for the reactions (1) νn→μp and (2)antineutrinop→μsup(+)n have been measured by using the data of the ν Gargamelle collaboration. 687 ν events, candidates for reaction 1), and 476 antineutrino events, candidates for the reactions 2), have been used for the analysis. Because the ν and antineutrino interactions are on nuclei, suitable corrections for nuclear effects have been taken into account. In the framework of the ''usual'' V-A theory, by assuming for the axial form factor the dipolar form Fsub(A)(q²)=1.231/(1+q²/Msub(A)sup(2)), our data have been fitted to the differential cross-sections dsigma/dq² integrated over the ν and antineutrino energy spectra and to the total cross-section sigmasub(el)sup(tot) as a function of the ν, antineutrino energy to determine the best value for the parameter Msub(A)

[en] Monte Carlo (M C) methods are considered one of the most powerful and precise approaches to study and solve medical physics issues. They, indeed, can be applied in all the situations where to use determistic algorithms is infeasible or impossible. Surprising improvements in computer technology have promoted a wide diffusion of this technique, giving rise to the born of several Monte Carlo codes, such as the GEANT4 tool kit. In this paper we show some of the application we developed using GEANT4. In particular, the simulation of two different radiotherapy techniques, such as proton/ion therapy and stereotactic radiosurgery will be discussed. In the first case we show the main features of our last public version of the GEANT4 Hadron therapy program, also discussing the issues related to the nuclear fragmentation. In the second case, we show the procedures followed for the simulation of a Gamma Knife device, in order to validate the Treatment Planning System (Tps) used for the dose computation.

[en] Nuclear reactor designs began their development in the 1940s and are categorized into generations. Up to the present day, only the Generation I, II and III reactors have come into full operation. However, the most widely used ones today are Generation II. In addition, Generation IV reactors are being developed. A group of countries, including Canada, Russia, Japan and the USA, came together to develop a new nuclear reactor generation, Generation IV. The main project objective is to improve the reactor's thermal efficiency, which currently remains around 30-36% to a level close to 50%. A international cooperation in research and development for the next generation of nuclear energy systems, known as the Generation IV International Forum (GIF) was formed and selected the six most promising systems from nearly 100 concepts such as Generation IV systems. This article emphasize the Gas-Cooled Fast Reactor (GFR), in view of the characteristics that make it very attractive for a feasibility check for its implementation in Brazil. The fact of maximizing the fuel use, together with the possibility of using the thermal energy produced for other purposes, such as hydrogen cogeneration, make it particularly exciting. Thus, it is possible to see the advantages that its incorporation could bring to the national scene, both in terms of energy production and in the waste reduction that can degrade the environment

[en] The improvement of the precision of the measurement of the nuclear cross-section, in order to fulfill the requirements of the actual Monte Carlo simulations for hadrontherapy and space radioprotection, is the main goal of the FIRST experiment. After a brief introduction on the treatment planning in hadrontherapy, this paper describes main characteristics and components of the experiment. The features of the interaction region detectors and their main needs (low material budget, high angular coverage, two tracks resolution and large trigger rate) are discussed. Special emphasis is devoted in discussing the new silicon pixel vertex detector, in particular its new developed data acquisition and its characterization with the first test results obtained with a prototype of the detector.

[en] New results about the simulation of Resistive Plate Chambers are reported; particular emphasis is put in the understanding of charge spectra in regions where deviations from the pure avalanche mode of operation can be present

[en] Two large double-gap resistive plate chambers, with 2 and 3 mm gap widths, were tested to study their response uniformity when operated in avalanche mode. The effects of mechanical tolerances and the presence of the spacers is thoroughly examined. Results on efficiency and time resolution are presented. We find that average performance and response uniformity over the whole chamber surface are fully adequate to the requirements of future collider experiments. (author)

[en] A study is presented of dimuon events from an exposure of BEBC to a wide band anti ν beam from the CERN SPS. These data double the available statistics on anti ν induced dilepton events observed in bubble chambers. The relative production rate and V⁰ yield have been measured and found to agree with previous experiments. The analysis of several kinematical variables shows that the gros features of the data agree with the predictions of the GIM model. Some indication exists that part of the signal could be due to quasi elastic production of the 'beautiful baryon', but the statistical significance is too weak to draw definitive conclusions. (orig.)