In this work the experimental results of a nonequilibrium laser-plasma induced by an ultraviolet 308 nm excimer laser are reported. All measurements were performed fixing the laser energy at 70 mJ. It was concentrated on a 0.0099 cm² spot by a convergent focal lens of 15 cm focal length. The utilized target was a 99.99% pure Cu disk. An 8 cm in diameter movable Faraday cup was developed in order to detect the plasma flow pulse at different positions along a drift tube. Analyzing the time-of-flight pulse under different cup bias voltage, we were able to distinguish the electron pulse, the suprathermal ions, and the thermal evolution of the plasma. In addition, by applying a breakdown voltage as polarizing cup voltage, we characterized the duration of the neutral component. To determine the system particle production efficiency, the total etched material per pulse, 0.235 μg, and the fractional ionization were measured. The expelled particle flux distribution was measured by an optical transmission analysis of a Cu deposited film on a glass substrate. The plasma flow was detected along its propagation axis, between 6 and 40 cm far from the target. The ablation process expelled particles with an initial velocity of 34 km/s, while the maximum ion concentration was 1 μs after the laser pulse. The plasma created propagates with a mean velocity of about 20 km/s. During the propagation, the longitudinal plasma dimension changed from 2.8 cm, near the target, to 31 cm at the maximum cup distance analyzed. At lowest distances, the cup signal wave forms presented a plateau due to the high dense plasma undergone to the space charge regime governed by the Child–Langmuir law.

The effects of laser fluence on the growth characteristics and surface morphology of yttrium films grown by pulsed laser deposition are investigated. The presence of droplets in the deposited films, which is the main drawback of pulsed laser deposition technique, was studied at different laser fluences. The morphology and the structure of the grown films were studied by scanning-electron microscopy and x-ray diffraction, respectively. Careful scanning-electron microscope investigations obtained by tilting the samples show that the droplets arrive to the substrate in the molten phase. The ablation rate measured at five different laser fluences (0.9–7.6 J/cm2) shows a nonlinear trend correlated with the presence of the plasma-shielding effect. The present interest in the deposition of yttrium thin films by laser ablation is due to the well-known photoemission characteristics of this metal. Depositing good-quality thin films with high adhension and low droplet density will improve the performance of photocathodes by reducing both the dark current and the thermal emittance of the photoemitted current.

The experimental results of particle acceleration by plasma generated using a XeCl laser are described. The laser ion source developed is able to accelerate specific particles and to overcome the plasma effects which occur specially during the application of the accelerating voltage. In order to successfully execute this experiment, plasma expansion was highly necessary before the accelerating voltage application. For this goal an almost hermetic expanding chamber with a hole at its end, used as extraction electrode, was made. In this way arcs were eliminated and specific particles propagate in the drift tube. Time-of-flight and current intensity measurements of the ion beam have been done. The output signal, measured at 147 cm from the target, resulted modulated on ion mass-to-charge ratio and its maximum current was $\text{220\hspace{0.5em}μ}\mathrm{A}$ at 18 kV accelerating voltage. Under the same accelerating value the bunch charge was estimated to be 4.2 nC.

Ultra-high-molecular-weight polyethylene (UHMWPE) is a versatile polymer employed in many fields for its good chemical–physics characteristics. In particular, it is widely utilized in biomedical fields due to its high degree of biocompatibility and its easy control on wettability of the surface. In this work, the laser radiation has been utilized to effect different degrees of change to the wettability characteristics of the UHMWPE depending on the laser used. The wettability modification was investigated by measuring the contact angles using the sessile drop method. It was observed that the interaction with laser wavelengths at 1064 and 532 nm effected very little change in the wettability characteristics of UHMWPE. On the contrary, the interaction of UHMWPE with 248 and 308 nm laser wavelengths resulted in a marked improvement in the wettability characteristics of the polymer; in particular, the UHMWPE irradiated by 308 nm, after 10 laser shots, reported a linearly increasing of the polymer wettability.