A comparison of the IR nanosecond laser ablation parameters for polished and nanostructured titanium samples has been performed. The titanium foil was mechanically polished and pres-structured by ...multiple 744-nm femtosecond laser pulses producing large surface spots covered by ripples with periods in range of 400–500nm. In order to evaluate the influence of such nanoripples, the nanosecond laser ablation and laser plasma properties were compared for polished surface, surface with nanoripples parallel and orthogonal to the laser beam polarization. A substantial decrease of the nanosecond ablation threshold was observed for the nanostructured in contrast to polished surface was detected while no influence of the ripple orientation vs. beam polarization was revealed. The comparison of plasma spectra for the ablation cases demonstrated that intensity of basic atomic lines and plasma emission duration were 2–5 times larger for the polished sample while spectra evolution was faster for the nanostructured sample. Plasma temperature and electron density were slightly lower for nanostructured sample while laser beam polarization has no effect on plasma properties.
•Laser ablation of polished and nanostructured titanium foils has been compared.•No influence of laser beam polarization on laser ablation threshold was detected.•Greater spectra intensity was observed for plasma formed on polished sample.•Plasma temperature and electron density were higher for polished sample.
One-dimensional periodic nanostructures have been produced on the surface of an aluminum specimen using femtosecond laser pulses at wavelengths of 744 and 248 nm. The nanostructurization of the ...specimen has been conducted in water and in air in the preablation regime. We investigate the dependence that the surface topology has on the parameters of laser radiation (wavelength, fluence, and number of pulses), as well as on the medium in contact with the specimen surface. A calculation of the optical characteristics of aluminum as they depend on the electron temperature is performed that is good at describing the dependence that the reflection of the
p
-polarized infrared femtosecond pulses of pumping has on the fluence. Using these optical characteristics of the photoexcited aluminum within the interferential model, periods of the aluminum surface nanogratings are estimated which are in good agreement with the periods measured experimentally.
The effect of irradiation with nitrogen ions (
E
= 30 keV,
J
= 10
16
−10
18
cm
−2
) on the elemental composition, surface topography, and structure of the near-surface layer of pyrolytic graphite are ...investigated.
The effect of an infrared pulse laser with femtosecond radiation (λ = 744 nm, τ ≈ 120 fs,
E
≤ 8 mJ) on the surface of Ti of commercially purity in the submicrocrystalline state is investigated using ...scanning electron microscopy (SEM). Laser irradiation leads to the formation of a surface nanorelief consisting of alternating projections (bars) and hollows (grooves). After surface treatment under a water layer, cube-shaped particles are formed on Ti surface; they are composed of many tightly contiguous rectangular plates.
Surface treatment of high modules carbon fibers by N + -beam have been carried out and changers in morphology and nitrogen concentration of carbon fibers as a function of the irradiated dose and have ...been investigated by using scanning electron microscopy (SEM) and Rutherford back scattering (RBS).
The performance of glass and sapphire substrate Micro Strip Gas Chambers with chromium and molybdenum electrodes overcoated with carbon, hydrogenated amorphous silicon and glass layers are reported.
Ion irradiation of carbon fibres Gavrilov, N.V.; Emlin, D.R.; Ligachev, A.E. ...
12th International Conference on High-Power Particle Beams. BEAMS'98. Proceedings (Cat. No.98EX103),
1998, Volume:
2
Conference Proceeding
The aim of the present work is to study changes of surface and volume physico-chemical properties of carbon fibres after ion irradiation. Ion irradiation of a foreign species can lead to the ...production of new compounds in near-surface layers of carbon fibre, but the displacement damage caused by energetic ions also lead to structural transitions of the surface layer.
