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Wyszukujesz frazę "laser-plasma" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Proton emission from laser - generated plasmas at different intensities
Autorzy:
Torrisi, L.
Cutroneo, M.
Cavallaro, S.
Giuffrida, L.
Margarone, D.
Powiązania:
https://bibliotekanauki.pl/articles/146370.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
laser-generated plasma
proton acceleration
Opis:
Proton acceleration from laser-generated plasma is carried out at intensities ranging between 1010 and 1019 W/cm2, by using ns, ps and fs laser systems. The high energy density transferred from the pulsed laser beam into the solid target generates ionized species released in vacuum from the solid surface. Fast electrons followed by slower ions build up a double-layer and a consequent electric field, which is responsible for the ion acceleration mainly along the target-normal. Polymeric targets containing nanostructures (or metallic species) with high laser absorbing capacity, and metallic hydrates (or H-enriched metals), permit to increase the plasma temperature and density, thus to improve the proton beam energy and current. Thick targets and low laser intensities, operating in repetitive pulse, allows to generate high currents of low energy protons. On the other hand, through the use of thin targets and high laser intensities enabled the generation of high proton energies, above 1 MeV.
Źródło:
Nukleonika; 2012, 57, 2; 237-240
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Post acceleration of ions emitted from laser and spark - generated plasmas
Autorzy:
Torrisi, L.
Cavallaro, S.
Rosiński, M.
Nassisi, V.
Paperny, V.
Romanov, I.
Powiązania:
https://bibliotekanauki.pl/articles/146658.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
post ion acceleration
laser plasma
ion beam
ion implantation
Opis:
Pulsed lasers at intensities of the order of 1010 W/cm2 interacting with solid matter in vacuum, produce hot plasmas at high temperatures and densities. The charge state distributions of the plasma generate a high electric field, which induces high ion acceleration along the normal to the target surface. The high yield of the emitted ions can generate a near constant current by using repetitive pulses irradiating thick targets. In order to increase ion energy, a post-acceleration system can be employed by using acceleration voltages above 10 kV. Special ion extraction methods can be employed to generate the final ion beam, which is multi-ionic and multi-energetic, due to the presence of different ion species and of different charge states. In this article four different methods of post ion acceleration, employed at the INFN-LNS of Catania, at the IPPLM of Warsaw, at the INFN of Lecce and at the LPI of Moscow, are presented, discussed and compared. All methods are able to implant ions in different substrates at different depth and at different dose-rates.
Źródło:
Nukleonika; 2012, 57, 3; 323-332
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Post-acceleration of ions from the laser-generated plasma
Autorzy:
Giuffrida, L.
Torrisi, L.
Powiązania:
https://bibliotekanauki.pl/articles/146664.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
laser ablation
laser-plasma
post-acceleration
ion implantation
Rutherford backscattering spectrometry (RBS) analysis
Opis:
An application of the laser-generated plasma for multi-energetic ion implantation is reported. In an experiment performed at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud (INFN-LNS) of Catania, Italy the Nd:YAG laser was used, operating at the 1064 nm wavelength with the intensity of 1010 W/cm2. A laser pulse of 9 ns duration and 300 mJ energy was employed to ablate a solid target placed in a high vacuum. The free ion expansion occurred in a constant potential chamber placed at 30 kV positive voltage with respect to the ground, which allowed to extract ions with energy proportional to the charge state. In an another experiment, performed at the PALS Prague laser facility (1315 nm, 400 ps pulse width and the laser pulse energy delivered on target equal to about 35 J) Ti ions were obtained through the ablation of solid targets in vacuum by means of 1015 W/cm2 laser pulses. In both cases ion energy analyzers were used to measure the energy-to-charge ratio of the ions. The ion energy distribution was determined from the time-of-flight measurements. The depth profiles measured through Rutherford backscattering spectrometry (RBS) analysis are in good agreement with the ion energy analyzer spectroscopy measurements.
Źródło:
Nukleonika; 2011, 56, 2; 161-163
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser-induced ablation: physics and diagnostics of ion emission
Autorzy:
Torrisi, L.
Powiązania:
https://bibliotekanauki.pl/articles/146624.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
laser-generating plasma
Boltzmann distribution
time-of-flight
Opis:
Pulsed lasers generating beams of different intensities may be used to produce ablation of solid targets placed in high vacuum and to generate pulsed plasma and ion acceleration. The plasma is in a non-equilibrium condition and in the first instant the particles being generated are subject to thermal interactions, to a supersonic gas expansion in vacuum and to a Coulomb acceleration due to the high electric field developed along the normal to the target surface. The ion diagnostics, based on time-of-flight technique, allow us to measure the mean ion energy, the total number of ions, as well as the ion energy and charge state distributions. The ion energy distributions may be described by the Coulomb- -Boltzmann-Shifted (CBS) function, which after fitting to the experimental data may be used to determine the equivalent ion temperature and the accelerating voltage. Given the equivalent acceleration voltage and the plasma Debye length, it is possible to estimate the magnitude of the electric field developed in the plasma. Measurements of the ablation yield, plasma dimension and optical spectroscopy allow us to calculate the atomic and electronic plasma density and to evaluate the coronal plasma temperature. Some applications of the laser-induced ablation consist in the realization of laser ion sources (LIS), generation of multi-energetic ion beams by using a post-accelerating voltage, use of ultra-intense fs lasers to accelerate ions to energies of the order of tens MeV/nucleon. Other special applications include the pulsed laser deposition (PLD) of thin films, the laser ablation coupled to mass quadrupole spectrometry (LAMQS) probes, ablation of biological tissues, and generation of plasma for astrophysical and nuclear investigations.
Źródło:
Nukleonika; 2011, 56, 2; 113-117
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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