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Extraction of negative ions from pulsed electronegative capacitively coupled plasmas J. Appl. Phys. 112, 033303 (2012) High electronegativity multi-dipolar electron cyclotron resonance plasma source for etching by negative ions J. Appl. Phys. 111, 083303 (2012) Decreasing high ion energy during transition in pulsed inductively coupled plasmas Appl. Phys. Lett. 100, 044105 (2012) Characterization and mechanism of He plasma pretreatment of nanoscale polymer masks for improved pattern transfer fidelity Appl. Phys. Lett. 99, 261501 (2011) Origin of electrical signals for plasma etching endpoint detection Time-and space-resolved emission and laser-induced fluorescence spectroscopic measurements were performed to investigate vaporization and plasma formation resulting from excimer laser irradiation of titanium targets in a low-pressure nitrogen atmosphere. Measurement series have been done by varying the laser intensity from the vaporization threshold at 25 MW crne2 up to values of about 500 MW cm-" typically applied in pulsed laser deposition processing of titanium nitride films. Thus, the transition from thermal evaporation to the high-density plasma formation process, leading to the production of reactive species and high-energy ions, was evidenced. An interesting result for the comprehension of the reactive deposition process was the observation of a quantity of dissociated and ionized nitrogen, which is transported with the plasma front in the direction of the substrate. 0 199.5 American Institute of Physics.

The local variation rates of a chaotic dynamical system provide a means of stroboscopic observation at adjustable times which minimize the second variation of the coordinates. The sequence of strobing intervals carries global information on the dynamics, yielding a suitable indicator which discriminates deterministic from stochastic signals. Due to the adaptive nature of the strobing process, the characterization of this indicator requires a computational effort much smaller than statistical methods.

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In this paper we intend to analyze a chaotic system from the standpoint of its computation capability. To pursue this aim, we refer to a complex chaotic dynamics that we characterize via its symbolic dynamics. We show that these dynamic systems are subjected to some typical undecidable and polinomially uneomputable problems. Our hypothesis is that these limitations depend essentially on the supposition of the existence of a fixed universal alphabet. The suggestion is thus of justifying a contextual redefinition of the alphabet symbols as a function of the same evolution of the system. We propose on this basis a general theorem for avoiding undecidable problems in computability theory by introducing a new class of recursive functions defined on different axiomatizations of numbers obtained by a modification of classical Peano's axiom of successor. In such a way, from an experimental viewpoint., we are able to obtain a very fast extraction procedure of unstable periodic orbits from a generic chaotic dynamics. The computational efficiency of this algorithm allows us to characterize a chaotic system by the complete statistics of its unstable cycles. Some examples of this technique applied to classical chaotic attractors are discussed. Finally we discuss some specific topic about pattern recognition and parallel computation. In this context we show how the same class of new recursive functions allows us to avoid some classical limitations demonstrated by Minsky and Papert in Perceptrons concerning the possibility of true parallel computations. These results are applied to the problem of reM time automatic recognition via software of particle tracks in high energy physics experiments.