Fluctuation analysis of meteo-marine data

We study long-term behaviour of air temperature, wave heights and wind speed time series recorded for the period 1993–1997 at a meteo-marine station located in the Adriatic Sea. The scaling analysis shows that fluctuations of air temperature display long-range autocorrelations, while those for wave heights show a more complex behaviour, crossing over from a persistent regime at intermediate time scales (up to about 20 days) to an anti-persistence behaviour at longer times. Furthermore, the crosscorrelations of their records are found to be large, with a covariance of about -0.3 (indicating anti-crosscorrelations) within the full 5-years period, giving a quantitative measure of the actual coupling between the two data sets. Wind speed fluctuations are found to be strongly crosscorrelated (about 0.6) with those of wave heights, indicating as expected that wind is the main driving force for wave height fluctuations.     

From the Anderson Model on a Strip to the DMPK Equation and Random Matrix Theory

We study weakly disordered quantum wires whose width is large compared to the Fermi wavelength. It is conjectured that such wires display universal metallic behavior as long as their length is shorter than the localization length (which increases with the width). The random matrix theory that accounts for this behavior—the DMPK theory—rests on assumptions that are in general not satisfied by realistic microscopic models. Starting from the Anderson model on a strip, we show that a twofold scaling limit nevertheless allows to recover rigorously the fundaments of DMPK theory, thus opening a way to settle some conjectures on universal metallic behavior.     

First track-structure measurements of 20 MeV protons with the STARTRACK apparatus

The STARTRACK experimental set-up, mounted on the +50° beam line of the Tandem-Alpi particle accelerator of Legnaro National Laboratories, has been conceived to give an experimental basis to nanodosimetric calculations. STARTRACK is based on a detection system able to measure ionization cluster distributions in a 20 nm propane site with a resolution of one ionization. The experimental layout has been designed to minimize pile-up distortions. The background noise is filtered by off-line dedicated software. Electron cluster distribution of 20 MeV protons has been measured. Monte Carlo data and experimental data are pretty well consistent.     

Contents of the Supplement B to Vol. 52 (2002)

Table of Contents

Contents of the Supplement B to Vol. 52 (2002)     

Millijoule-level phase-stabilized few-optical-cycle infrared parametric source

Ultrabroadband self-phase-stabilized near-IR pulses have been generated by difference-frequency generation of a filament broadened supercontinuum followed by two-stage optical parametric amplification. Pulses with energy up to 1.2 mJ and duration down to 17 fs are demonstrated. These characteristics make such a source suited as a driver for high-order harmonic generation and isolated attosecond pulse production.     

Beta decay of <Superscript>115</Superscript>In to the first excited level of <Superscript>115</Superscript>Sn: Potential outcome for neutrino mass

Recent observation of β decay of ¹¹⁵In to the first excited level of ¹¹⁵Sn with an extremely low Q _β value (Q _β ≤ O(1) [keV]) could be used to set a limit on neutrino mass. To give a restriction potentially competitive with those extracted from experiments with ³H (≃2 eV) and ¹⁸⁷Re (≃15 eV), the atomic mass difference between ¹¹⁵In and ¹¹⁵Sn and energy of the first ¹¹⁵Sn level should be remeasured with higher accuracy (possibly of the order of ∼1 eV). The text was submitted by the authors in English.     

Improvement in underwater phase measurement of an amplitude-modulated laser beam by polarimetric techniques

The phase of the amplitude-modulated radiation reflected by a Lambertian target immersed in water was measured by using a linearly and circularly polarized sounding laser beam. Different values of the water extinction coefficient in the range of 0.06 - 2 m(-1) were realized by adding skim milk as a scattering element. It is shown that very efficient rejection of optical noise, resulting in reliable phase measurements, is accomplished with a cross-polarized and copolarized detection scheme for linear and circular polarization, respectively. The experiment demonstrates that phase measurements are very sensitive to optical noise suppression and that, as far as single scattering is the main involved mechanism, significant improvements can be achieved by adopting a polarization control on both the transmitter and the receiver stages of the apparatus.