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Titanium dioxide is a technologically interesting material in many applicative fields that, however, exhibits critical aspects in terms of phase purity and synthesis/growth conditions. The presented work deals with the deposition, in vacuum, of single-phase rutile and anatase titania films by excimer laser ablation (λ = 248 nm) of anatase and rutile targets. Post-deposition thermal treatment at 450 °C in air was applied to drive the crystalline evolution of the as-deposited films, limit oxygen desorption and avoid changes in the polymorph phase. Unlike the typical use of oxygen as a background gas and Ti target in pulsed laser deposition of TiO2, our setting vacuum background atmosphere not only allows to relate the final phase of the film directly to the target phase but also to rule out phase transitions and mixed-phase, by the interplay between post-growth temperature and limited oxygen desorption. Herein, we study and discuss how the ablation process impacts on and determines film composition and morphology. The discussed influence of the target phase on the optical, morphological and photocatalysis properties of the titania films points out good performances of our samples and the importance to tune deposition to obtain the titania polymorph phase more suitable for specific applications.

In this paper, we present an investigation on two types of nanodiamond (ND) powders with average size of particles around 250 nm and having different sp2 (graphite phase) and sp3 (diamond phase) carbon contents. The ND surface modification is carried out by physical methods i.e. treatments in H2 microwave plasma. The quantum efficiency (QE) of photocathodes and the stability of aqueous dispersions are assessed by photoemission and zeta potential (ZP) measurements, respectively. The resultant hydrogenated surface affects in the solid state the QE of ND-based photocathodes and in solution the particle ZP. The effect of the hydrogen treatment is beneficial inducing an enhancement of photocathode QE and a corresponding increase of the ZP. A schematized energy diagram is proposed to illustrate and explain the strong correlation between QE and ZP parameters.

Zebrafish (Danio rerio) embryos were subjected to different physical stresses, consisting of a static and two low frequency magnetic fields, and two radiofrequencies. Embryos were exposed to static (Bo, 0 Hz), very low frequency (VLF, 0.2 Hz), low frequency (LF, 270 kHz), very high frequency (VHF, 100 MHz), and ultra-high frequency (UHF, 900 MHz) magnetic field irradiation for up to 5 days. The field intensities were 40 mT, 40 mT, 470 µT, 240 nT and 240 nT, respectively. Untreated embryos were used as control.(n= 10 for each condition).

The European Rail Research Advisory Council (ERRAC) was set up in 2001 with the goal of helping to revitalise the European rail sector by making it more competitive, fostering increased innovation and guiding research efforts at the European level. The ERRAC Project Evaluation Working Group (EWG) determines the market impact of previous rail research to improve use of research funding and to ensure a strategic approach to the prioritisation of rail research. Individual projects are evaluated after they have been completed to ensure successful dissemination of project results in order to ensure that the results of previous rail research can be taken into account for future projects and avoid weak market uptake of results by learning the lessons of previous research.The EWG provides intelligence based on the project evaluations for input into future European Framework Programmes. ERRAC EWG has evaluated over 50 finished projects from the ERRAC database which has details of all Rail-related past and current rail research funded by the European Commission. A methodology has been developed to evaluate the market impact of projects and assess the contribution of evaluated projects to the ERRAC ROADMAPS and Strategic Rail Research Agenda (SRRA) goals. This information provides inputs to EC Project officers during the negotiation phase and during the course of the projects for project review.EWG has evaluated successfully finished rail research projects in order to analyse the success/failure factors related to actual market uptake and determine market uptake from an industry perspective in order to determine the return on research investment. This coordination activity helps to provide ideas for new European and national projects with a real potential for implementation and therefore a significant market uptake. The ERRAC EWG has developed the database to provide rapid access to information on results of rail research projects, deliverables etc., as well as lessons learnt and possible contributions to the attainment of the goals of the Rail Vision 2020 in coherence with SRRA and in the future RAIL VISION 2050.

We study the velocity distribution of ions delivered by plasma whihs is induced by UV Laser.

In this work, we report on the characterization of pulsed soft X-rays emitted from laser-produced plasma by different targets. The measurements were performed in a vacuum stainless-steel chamber at 10-7 mbar .The plasma was generated by a pulsed KrF excimer laser of 248 nm laser wavelength, operating at single shot and having a pulses of 23 ns FWHM. The beam was focused on pure Si, Cu and Ta targets. The laser energies were 40, 80 and 120 mJ, concentrated onto a spot of about 0.01 cm2, with a resulting irradiance of 1.7, 3.5 and 5.2x108 Wcm-2. The utilized detector was a very sensitive Faraday cup which opportunely biased was able to record time resolved signals of X-rays and to estimate their energy. The found X-rays energy values were compared to the ion temperature of the target plasma fitting the time resolved ion current signals by the shifted Maxwell-Boltzmann velocity distribution.

We developed an ion accelerator with a double accelerating gap system supplied by two power generators of different polarity.-The ions were generated by laser ion source technique. The laser plasma induced by an excimer KrF laser, freely expanded before the action of accelerating fields. After the first gap action, the ions were again accelerated by a second gap. The total acceleration can imprint a maximum ion energy up to 160 keV per charge state. We analyzed the extracted charge from a Cu target as a function of the accelerating voltage at laser energy of 9, 11 and 17 mJ deposited on a spot of 0.005 cm2. The peak of current density was 3.9, 5.3 mA for the lower and medium laser energy at 60 kV. At the highest laser energy, the maximum output current was 11.7 mA with an accelerating voltage of 50 kV. The maximum ion dose was estimated to be of 1012 ions/cm2. Under the condition of 60 kV accelerating voltage and 5.3 mA output current the normalized emittance of the beam measured by pepper pot method was 0.22 π mm mrad.

In this work two different techniques to modify the polymeric surfaces are compared; Laser irradiation and ion implantation were performed on Ultra High Molecular Weight Polyethylene (UHMWPE) samples. The irradiation treatment was performed by using two different laser sources operating in the UV and IR range, applying many laser shots in air atmosphere on the polymer surface. Ion implantation was performed using a new LIS (Laser Ion Source) accelerator with an accelerating voltage of 40 kV. Contact angle, roughness and Fourier Transform Infra Red (FT-IR) measurements were performed on the samples before and after the two treatments in order to obtain information on the UHMWPE modification.

The properties of pulse laser ablation of Cu and Cu98/Be2 materials are studied and the differences in emission of Cu ions are emphasized. The iodine high-power laser system PALS and a KrF laser were used to perform the experiments at the fundamental harmonics λ = 1.315 µm and  = 248 nm delivering energy up to 500 J and 600 mJ, respectively. Pure Cu and Cu98/Be2 alloy targets of 50 µm, 500 µm and 1000 µm in thickness were ablated to measure the influence of the Be admixture on the emission of Cu ions. The alloy Cu98/Be2 was chosen due to the well defined amount of a beryllium admixture in the plasma in contrary to the incidental amount of carbon, oxygen and hydrogen impurities chemisorbed on target surfaces of Cu and Cu98/Be2 samples. It was approved that the emission of Cu ions driven by the KrF laser exhibits a higher gain from the Cu98/Be2 plasma in contrary to the Cu plasma. The fast ion emission induced by laser intensities near the threshold value is significantly affected by the emission of ionized impurities chemisorbed on the target surface and by repetitive outbursts of fast generated ions. Under these conditions the influence of the 2% Be admixture on the emission of Cu ions plays only a minor role.

Nanodiamond (ND) layers are produced by the pulsed spray technique on a heated silicon substrate. By varying the number of pulses it was possible to obtain a quasi-continuous layer on the substrate surface. The use of atomic force and confocal microscopies allowed to evidence the presence of self-assembled pillar structures. The pillar formation is due to the evaporation of 1,2-dichlorethane solvent in which 250 nm nanodiamonds were dispersed and its mechanism is based on the coffee stain effect as described in detail in ref. 1. Simple bio-chips on glass and silicon substrates can be fabricated spraying ND spots arranged in an array configuration (see Figure 1a) through a mask, and are suitable for bio-applications. Specifically, the presence of nitrogen vacancy (N-V) color center in ND particles is also promising as bio-markers2. An example of spot is illustrated in Figure 1b where pillars are present (see the zoomed area of Figure 1b). Additionally, the control of the pillar position represents an important challenge for micro-functionalised emitters arranged in a chip matrix suitable for bio-screening.

This 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 108 W/cm2 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.

Light emission from porous silicon is known since several years. Recently, the ability of silicon nanocrystals (NCs) or nanoclusters embedded in a suitable dielectric (usually silicon oxide - SiO2) matrix to efficiently emit photons in the visible spectral region has been demonstrated; potential applications of these nanostructures are in the field of monolithically integrated Si-based photonic devices. Si NCs have been fabricated by a variety of methods, including co-sputtering, chemical vapour deposition, molecular beam epitaxy, gas evaporation, laser ablation, and ion implantation (at ion energies from 100 keV up to a few MeV) followed by high temperature annealing. The latter methodology has the advantage that a controllable dose of ions can be placed at a given depth and distribution into the dielectric medium. High temperature annealing of implanted samples leads to Si atoms precipitation and NC nucleation. In this work we present preliminary results on the synthesis of Si NCs by low (10-40 keV) energy implantation of Si ions into SiO2 films and their subsequent high temperature annealing.

A novel technique for ion implantation of electronics materials by means of a laser ion source emitting multi-energetic ion streams was investigated. A UV pulsed laser beam, at intensities of the order of 108 W/cm2, was employed to produce plasma in a vacuum from a Ge target. The apparatus utilized was very versatile and able to contain an expansion chamber in order to allow the plasma to be diluted before the application of an accelerating voltage. The mean ion energy increased with the laser pulse energy and the ion charge state, and ranged between about 100 eV and 1 keV. To increase the ion energy a post-acceleration up to 50 kV was employed, which resulted in ion energies from about 50 keV to about 150 keV, depending on the charge state. The multi-energetic ion beam, with current density of the order of 10 mA/cm2, was employed to irradiate silicon substrates and to obtain surface implantations up to a depth of about 150 nm. During the implantation process the ion beams were generated with a repetition rate of the laser pulse of 1 Hz. The depth profiles of the ion implants were investigated by Rutherford backscattering spectrometry and laser ablation – inductively coupled plasma – mass spectrometry.

This work is devoted to characterizing the ion current changes resulting in a laser-plasma in free expansion near the irradiated target. In this zone, in fact, the plasma density is very high and the plasma charged particles are subjected to recombination processes which induce changes in the chargestate abundances. The recombination end occurs after the dilution of plasma density and the laser-plasma keeps on expanding in vacuum characterized by steady charge and energy distribution of the ions. The knowledge of distance, where the charge states of ions are not affected of changes any more, is essential to develop a laser ion source where the extraction of ions from the laser-produced plasma is required

The precise characterization of plasmas generated by laser irradiation is needed for the development of ion sources. Since the characteristic parameters of the expanding plasma vary on both the distance and the time, an experimental study of their evolution is appropriate for a deeper knowledge of the plasma. The purpose of this work is to study same characteristics of laser plasma produced by ablation of a pure Cu target as function of the distance from the target along the propagation axis of the plasma plume. We irradiated the target by a KrF laser and a lens of 15 cm focal length. As the diagnostic system, a small Faraday cup array and an axial Faraday cup were utilized to study the spatial variation in the total charge carried by plasma ions. Charge loss during the plasma expansion was observed due to the recombination of charged species, which occurs within a critical distance, relatively close to the target, where the plasma density is high enough. The critical distance was determined for different laser fluences; beyond the critical distance the collisions among plasma particles are negligible and the ion charge remains frozen. It was observed that the critical distance increases as the laser fluence increases.

Il diamante è considerato un materiale molto promettente per lo sviluppo di dispositivi per la rive-lazione di radiazione UV grazie alle sue peculiari pro-prietà chimiche e fisiche (in particolare ottiche ed elettriche). In questo lavoro sono presentati i risultati ottenuti su dispositivi basati su film di diamante poli-cristallino ROD (Random Oriented Diamond), pro-dotti con la tecnica MWPECVD (MicroWawe Plasma Enhanced Chemical Vapour Deposition) su substrati di silicio intrinseco e drogato-p (100). Sui dispositivi realizzati è stato eseguito uno studio comparativo in funzione del tipo di substrato e del diverso passo tra gli elettrodi di Cr/Au complanari ed interdigitati. So-no state quindi determinate le proprietà chimico-strutturali, morfologiche, elettriche ed ottiche dei film. In particolare, la risposta ottica è stata misurata in aria, utilizzando una lampada impulsata allo Xe accoppiata con una fibra ottica di quarzo, filtri inter-ferenziali per selezionare la lunghezza d"onda ed un"elettronica di misura di read-out basata su un am-plificatore sensibile alla carica a basso rumore. I ri-sultati sperimentali evidenziano una dipendenza delle prestazioni del dispositivo dal tipo di substrato utiliz-zato e dalla geometria dei contatti interdigitali.

Diamond is considered as a very promising material for the development of devices for radiation detection. Unlike other conventional photoconductive detectors diamond-based devices should provide high discrimination between UV and visible radiation. In this work we present the electro-optical properties of devices based on randomly oriented diamond films, synthesized in a microwave plasma enhanced chemical vapor deposition reactor. A comparative study on devices with coplanar interdigitated Cr/Au electrodes (with different interelectrode pitches) made of films grown simultaneously on intrinsic and p-doped silicon (100) substrates has been performed. The chemical–structural, morphological, electrical and optical properties of ROD films have been studied. In particular, the optical response has been measured in air using a Xe flash lamp coupled with an optical quartz fiber and a properly tailored front-end electronics based on a charge sensitive amplifier. Experimental results gave indications on how the device performances are dependent on the two types of employed substrates.

A new classification of laser ion sources concerning their pulse‐to‐pulse reproducibility in the ion emission is proposed. In particular, we distinguish between plasmas according to the electron distribution changing its characteristics at a laser intensity threshold of 1014 W/cm2. Well reproducible continuous pulsed ion currents are typical for the intensity below the threshold. In contrast to this plasma the “two‐temperature” plasma arising for the intensity above this threshold shows not only a separation of charges in space and time but it also shows irregular and intense outbursts of ions similar to a self pulsing instability leading to a chaos. The sequence of fast ion outbursts visible on time‐of‐flight spectra is sensitive to details of non‐linear interaction of the sub‐nanosecond laser beam with the generated plasma.

In this work we explore the consequences on variable magnetic fields applied to radish seeds (Raphanus sativum L.) on germination and seedling growth. Three, different alternate magnetic fields have been tested having a high intensity, 40 mT, at very low frequency, 0.2 Hz (B0. 2), a low intensity, 577 µT, at low frequency, 370 kHz (B370), and a very low intensity, about 250 nT, at ultra high frequency, 900 MHz (RF900). These last generate electromagnetic waves which are nowadays very used for mobile communications. Groups of uniform radish seeds were exposed to alternate magnetic fields at three duration time values: i) 120 h (BO. 2/1), 260 h (B0. 2/2) and 360 h (B0. 2/3) at high intensity and very low frequency, 0.2 Hz; ii) 120 h (B370/1), 260 h (B370/2), 360 h (B370/3) at low intensity and low frequency, 370 kHz; iii) 120 h (RF/1), 260 h (RF/2), 360 h (RF/3) at very low intensity and ultra high frequency, 900 MHz. Furthermore, another group of seeds was treated by laser beams of 248 nm wavelength whose magnetic field is coupled to an electric field. These two fields, by the Planck theory, origin the quantum energy, expresses by photons. Therefore, in the laser-matter interaction photons are absorbed dependent on laser shots. Again, we performed experiments at three duration time values that applied: 30 kshots (KrF/1), 80 kshots (KrF/2) and 135 kshots (KrF/3) at 40 mJcm2/fluence. The magnetic field and electric field presented by the laser beam are approximatively 250 kVm/and 850 µT, respectively. All treatments were performed at room temperature. Both untreated seeds and each group of seeds exposed to the physical stresses were …

A new LIS configuration was studied and realized in order to generate and accelerate ions of different elements. This ion source consisted of a laser-induced plasma from solid targets where the plume was made to expand before the action of the accelerating field. The accelerating field was reached by the application of two high voltage power supplies of different polarity. Therefore, the ions were undergone to double acceleration which can imprint a maximum ion energy up to 160keV per charge state. We analyzed the extracted charge from a Cu target as a function of the accelerating voltage at the laser fluence of 1.7 and 2.3 J/cm^2. At 60kV of total accelerating voltage and higher laser fluence, the maximum ion dose was of 10^12 ions/cm^2. Under this last conditions the maximum output current was 5 mA and the emittance measured by pepper pot method resulted of 0.22 π mm mrad. By this machine biomedical materials as UHMWPE were implanted with carbon and titanium ions. At doses of 6x10^15 ions/cm^2 the polyethylene surface increased its micro hardness of about 3-hold measured by the scratch test.

High intensity ion beams can be obtained by laser plasma or applying high electric fields or utilising large acceleration gaps. We get it developing a double acceleration gap system supplied by two power generators of different bias voltages. In this way we realized a new LIS accelerator configuration in order to produce and to accelerate ions of different elements. The LIS consists of a laser-induced plasma from solid targets, where the plume freely expands before the action of the accelerating fields. Our system provides ion beams of maximum energy up to 160 keV per charge state. We extracted charge from a Cu plasma as a function of the accelerating voltage at laser fluence values of 1.8, 2.2 and 3.4 J/cm 2 . At 60 kV of total accelerating voltage, the peak currents were 3.9 and 5.3 mA corresponding to 1.8 and 2.2 J/cm 2 laser fluences, respectively. At the highest laser fluence, the maximum output current was 11.7 mA with an accelerating voltage of 50 kV and a corresponding ion flux of 10 12 ions/cm 2 . Under the condition of 60 kV accelerating voltage and 5.3 mA output current (ion flux 3.4×10 11 ions/cm 2 ) the normalized emittance of the beam measured by pepper pot method resulted of 0.22π mm mrad. Under the condition of 160 kV accelerating voltage the ion flux was higher than 1.0×10 11 ions/cm 2 .

In the last years the ion component of a laser-produced plasma has been considered and studied as an object to provide high-density ion sources, which can be applied in many fields such as laser-induced implantation. In this work a KrF laser beam of 108 W/cm2 irradiance was focused onto single-crystalline Fe and single-crystalline Fe with 2% of Si targets and the characteristics of both free expanding laser-produced plasmas were compared. The time-of-flight (TOF) method was applied to determine the ion charge yield at various laser fluences and the ion angular spread. The analyses of TOF spectra showed a synergetic effect of the silicon admixture in target material on the Fe ions production. Besides, this admixture was also responsible of the increasing of the plasma temperature which corresponds in turn to the increasing of the average kinetic energy of the particles as well as of the more collimated ion distribution.

Metallic and non-metallic ion beams can be used to modify the properties of wafer surfaces if accelerated at a moderate energy. We developed a new “implantation machine” able to generate ions and to accelerate them up to 80 kV. The ion generation is achieved by a laser-plasma source which creates plasma in expansion. The device consists of a KrF excimer laser and a generating vacuum chamber made of stainless steel. The laser energy was 45 mJ/pulse, providing a laser fluence of about 4.5 J/cm2 and a power density of 2.25x108W/cm2 by means a convergent lens. The target support was a stem mounted on an insulating flange and kept to positive voltage to accelerate the produced ions. The ion dose was estimated by a fast Faraday cup polarised at negative voltage. This machine was utilised to try synthesizing silicon nanocrystals in SiO2 matrix. In this work we present the preliminary results of Si ions implanted onto SiO2 films and the glancing-angle X-ray diffraction analyses.

Complex systems are experiencing increasing needs to obtain a higher level of safety and to reduce time to market. This is in particular true for automotive, aerospace and railway domains, pushing the research community to define novel development and verification methods and techniques. The ARTEMIS EU-project MBAT (Combined Model-Based Analysis and Testing of Embedded Systems) represents one of the most important attempts in this direction since it aims to achieve such improvements in several application domains. Starting from the Ansaldo STS implementation of Communication-Based Train Control system (CBTC), which is the base of automatic driverless metro systems, we describe in this paper the improvement that MBAT would bring to the Verification process. To this aim an accurate description of existing Verification process in automatic metro systems and discussion about critical points are provided. Then we describe the expected results of MBAT project on such kind of processes. The proposed approach and developed tools will be part of a common reference platform and, also if related to the railway domain, for its generality, they can be used for different domains with similar needs. The basic agreement in the project will guarantee the cross use of the platform and will give quantitative measures of the obtained improvement.

In this work we report on the characterization of pulsed soft x-rays emitted from laser-produced plasma. The plasma was generated by a pulsed KrF excimer laser focused on pure Si, Cu and Ta targets by 40, 80 and 120 mJ laser energies. The utilized detector was a very sensitive Faraday cup which opportunely biased was able to record time-resolved signals of x-rays and to estimate their energy. The found x-rays energy values were compared with the ion temperature of the plasma obtained by fitting the time-resolved ion current signals with a shifted Maxwell-Boltzmann velocity distribution. The results showed that the laser-produced Ta plasma induced bunches of x-rays having in average the highest energy values and it was also characterized by ion temperature higher than the ones of the laser-produced Si and Cu plasmas.