1,721,120 research outputs found
Sistemi di Pd caricati con D2 e H2 gassosi e irradiati da fasci laser
No full textL’attività di ricerca sulla fusione fredda, presso il laboratorio LEAS, nasce dopo la pubblicazione dei sorprendenti risultati sperimentali ottenuti da Fleischmann e Pons [1] nel 1989.
Il metodo di caricamento gassoso di D2 o H2 dei campioni di Pd è stato preferito al tradizionale caricamento per via elettrolitica in quanto il sistema metallo-gas è più semplice da monitorare e comporta delle condizioni di lavoro più pulite. L’interesse della ricerca del laboratorio LEAS, è stato rivolto principalmente a migliorare le condizioni di caricamento dei sistemi metallo-gas, realizzando specifiche camere in acciaio inox
ASIMMETRY IN ELECTRON AND ION CHARGE COLECTION IN A DRIFTING PLASMA BUNCH
No full textWe report on the different behavior of electron and ion currents recorded by a Faraday cup in a
plasma bunch generated via laser ablation. An excimer laser was employed to irradiate a Ge target.
The current signals were recorded equipping the Faraday cup collector by a set of diaphragms. We
found that the electron time-of-flight spectra were fairly similar to the ion ones, but the collected
charge yield for electrons was up to 200 times larger than the corresponding ion yield. We ascribed
such a discrepancy to the different cup collection efficiency for ions and electrons forming the
plasma which was heavily influenced by the plume geometry, the energy of the particles, as well as
the diaphragm size. Our findings would suggest that the overall electron charge “tended” to be
collected, unlike the ion charge which scaled upon the collection solid angle
Detailed mass spectrometric studies during laser ablation of Yttrium target in high vacuum
No full text
FCD Fast Capacitive Divisor
No full textIl trovato è un divisore capacitivo di dimensioni tali da registrare impulsi molto brevi inferiori a 100 ps.
Le applicazioni sono da trovare nel campo delle macchine acceleratrici e di diagnostica digitale
Fast Capacitve Probe for Electromagnetic pulses diagnostic
No full textGeneration of electromagnetic pulses of fast and high intensity is constantly in progress. The real time diagnostic of short current or voltage pulses is essential for good application with sophisticate and modern devices. Streak camera systems are able to detect sub ps pulses of particle or X-ray beams, but losing the possibility to use the beams during the detection. Besides, real time measurements of electromagnetic pulses offer a better control of the device functioning. Nowadays fast current or voltage pulses of sub ten picoseconds can be recorded in real time by means of modern fast digitizing oscilloscopes, but to get good results it is necessary to realize fast probes. Fast capacitive probes, which we will present in this work, are simple capacitors conceived like a transmission line. For this reason it is indispensable to construct them with electrodes of suitable dimensions and forms, e.g., i: the probe has to got a folded central electrode in order to present the internal skin dimensions close to external ones, ii: it has to got a particular configuration able to contain and to shield the integrating resistor avoiding electromagnetic irradiations. Such a probe is suitable for measuring fast voltage and current pulses propagating in coaxial structures of known characteristic impedance. Analysing the behaviour of the probe in a 50 Ω coaxial structure, the voltage amplification resulted to be of (3.6±0.1)x10-4 and as a consequence the current attenuation factor of 56±1 A/V. The rise time response was very interesting. It was less than 320 ps, which was limited by oscilloscope bandwave. In vacuum electrical devices the capacitor probe can measure potential values of the order of 100 kV
Probe per impulsi veloci
No full textIl trovato è utile per la diagnastica di impulsi veloci. Può essere applicato per misurare fasci di corrente di ioni o elettroni, ed altro
IRIDE: Interdisciplinary research infrastructure based on dual electron linacs and lasers
No full textCharacterization of laser-produced plasma of metal targets
No full textThis work has the purpose to characterize the plasma produced by solid target ablation. The experiment was performed by using a KrF laser with an irradiance of 10(8) W/cm(2) and different solid targets, i.e., Si, Ge, Pd, and Pb. A very suitable Faraday cup has been utilized to study the angular distribution of the plasma plume as well as to perform measurements of the ion charge carried by the plasma during its free expansion into the vacuum. Particular attention was done to estimate the charge losses ascribed to the recombination processes during the plasma expansion. Different charge angular distributions have been found for the four laser-induced plasmas which suggest the dependence of the plasma characteristics with the different physics processes involved during the laser-target and laser-plasma interaction. These processes are responsible also of the duration of the recombination processes which results to be different according to the different plasma
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