G. Battistoni

Experimental Study of Atmospheric Neutrino Flux in the NUSEX Experiment

The fully contained events detected in the NUSEX nucleon stability experiment have been analysed to search for possible anomalies in the fluxes of atmospheric neutrinos. The measured flux of muon neutrinos is in very good agreement with predictions and no anomaly has been found in the ratio between the rate of electron and muon neutrino events.

The NUSEX detector

Abstract We present in this paper the characteristics, trigger system and performance of the NUSEX detector, designed to study nucleon stability, running in the Mt. Blanc laboratory.

Response of streamer tubes to highly ionizing particles

Abstract The charge response of streamer tubes has been measured as a function of ionization power by exposure to relativistic ions. The results are discussed in view of the use of streamer tubes in the search for magnetic monopoles.

Primary cosmic-ray spectrum at energies ∼(1013÷1016) eV from multiple muon events in NUSEX experiment

SummaryThe multiple-muon rates measured in the NUSEX experiment at a vertical depth of 5000 hg/cm2 s.r. are compared with some current models of the primary cosmic-ray composition. Monte Carlo simulations as well as analytical formulae which take into account the geometrical and acceptance features of the apparatus have been used in calculations. A good agreement is found with a model in which the relative fraction of primary heavy nuclei does not increase significantly up to about 1016 eV. This model reproduces very well both the all-nucleon flux measured in the range (1013÷1014) eV and the all-particle spectrum up to 1016 eV.RiassuntoLe frequenze di muoni multipli ottenute con il rivelatore NUSEX ad una profondità verticale di 5000 hg/cm2 sono confrontate con diversi modelli sulla composizione di primari cosmici. Questo studio è fatto usando Montecarlo e formule analitiche che tengono conto degli aspetti geometrici e dellaccettanza dellapparato. Un buon accordo è trovato con un modello nel quale la relativa frazione di nuclei pesanti non cresce significatamente fino a 1016 eV. Questo modello riproduce bene sia il flusso totale di nuclei misurato nellintervallo (1013÷1014) eV che lo spettro di particelle fino a 1016 eV.РезюмеИнтенсивности множественных мюонных событий, измеренных в NUSEX эксперименте на глубине 5000 hg/cm2 s.r., сравниваются с имеющимися моделями первичного состава космических лучей. При вычислениях используются моделирования по методу Монте-Карло и аналитические формулы, которые учитывают геометрические характеристики аппаратуры. Получается хорошее согласие с моделью, в которой относительная доля первичных, тяжелых ядер существенно не увеличивается вплоть до энергий 1016 эВ. Эта модель очень хорошо воспроизводит поток всех нуклонов, измеренных в области (1013÷1014) эВ, и спектр всех частиц вплоть до 1016 эВ.

Plastic spark counters with PVC electrodes

Abstract The performance of a spark counter based on plasticized PVC is described. The relevant features of this detector match the requirements of surface and underground cosmic ray experiments. Its technological characteristics allow large area detector construction.

An experimental study of the neutrino background in underground experiments on nucleon decay

Abstract In order to investigate experimentally the background induced by atmospheric neutrinos in nucleon decay experiments we have simulated very closely the expected spectrum by means of an accelerator produced neutrino beam and exposed to it a test module of a fine train calorimeter. Two runs have been performed with the detector axis placed at 0° and 45° with respect to the neutrino beam direction, and a total of 400 events have been detected and measured. The background induced by atmospheric neutrinos into various nucleon decay channels has been deduced from these data. These results can be applied to the present or planned nucleon decay experiments.

Cosmic-muon results from the NUSEX experiment

SummaryMuon underground data collected in the NUSEX experiment at Mont Blanc have been analysed concerning the following topics: I) vertical muon intensity, II) prompt muon flux, III) muons from the direction of Cygnus X-3. Preliminary results from the analysis of more than 20 000 muons are presented and discussed.RiassuntoGli eventi di muoni rivelati sottoterra nellesperimento NUSEX al Monte Bianco sono stati analizzati per studiare I) lintensità verticale dei muoni, II) il flusso di muoni pronti, III) leccesso di muoni dalla direzione di Cygnus X-3. In questo lavoro sono presentati c discussi i risultati preliminari ottenuti dallanalisi di piú di 20.000 eventi.РезюмеБыл проведен анализ данных, собранных в экспеимемнте NUSEX на Мон Блане. Анализировались следующие вопросы: 1) интенсивность вертикальных мюонов, 2) поток мгновенных (быстрых) мюонов, 3) мюоны, движущиеся в направлении от Лебедь X-3. Приводятся и обсуждаются предварительные результаты анализа для более, чем 20 000 муонов.

Use of large size streamer tubes in cosmic ray experiments

Abstract The influence of gas composition on charge distribution and stability of operation of streamer tube chambers with 3 × 3 cm 2 cell size has been studied. The possibility of using these chambers without continuous has circulation has blso been investigated in view of their use in large arrays operating in cosmic ray experiments.

The use of n-hexane in the gas mixture for streamer tubes

Abstract We have investigated the use of n-hexane as a quencher in the gas mixtures for streamer tubes. We discuss the advantages of this choice from the point of view of safety.

A high voltage network for streamer tubes

Abstract We have studied a high voltage network which allows the simultaneous readout of strips and pads for the streamer tubes of the ALEPH hadron calorimeter. The mechanisms of pulse propagation in streamer tubes are discussed, together with the results of experimental tests made with the designed high voltage network configuration.