Dynamics and density distribution of laser-produced Al plasmas using optical interferometry and optical emission spectroscopy

Two-dimensional axisymmetric radiation hydrodynamics model of moderate-intensity nanosecond laser-produced plasmas

“…In this paper, interferograms (not shown) of Al plasmas in air at atmospheric pressure were obtained in Mach-Zehnder interferometry introduced in section 3. Based on a two-dimensional fast Fourier transformation algorithm [63] and an inverse Abel transformation [48,64], the phase shift information and the radial distribution of the refractive index were extracted from the interference fringes, and finally the two-dimensional electron density distributions (not shown) were obtained. Figure 13 depicts the comparison between the numerically simulated and the experimentally measured electron density along the axial direction at r = 0 when the delay times are 300, 500, 800, and 1000 ns.…”

“…In this paper, multiple experimental measurements including fast photography, temporal-spatially resolved optical emission spectroscopy (OES), laser interferometry, and shadowgraphy images are performed, and the experimental results are used to benchmark the radiation hydrodynamic model. We have reported the details of several experimental devices in our previous work [47,48], so this paper only provides some brief descriptions. The laser used to generate plasma in different experimental measurements had a Gaussian-shaped pulse with a peak intensity of 5 × 10 8 W cm −2 , wavelength of 1064 nm, and full width at half maximum (FWHM) of 10 ns.…”

Prediction of Shock Wave Velocity Induced by a Combined Millisecond and Nanosecond Laser Based on Convolution Neural Network

“…From a macro perspective, this produces a certain recoil pressure on the target. Scholars from all over the world have mainly studied the short-pulse-laser-induced shock-wave pressure field [7][8][9][10]. For example, J. Radziejewskaa et al studied the velocity and pressure of a shock wave produced by a nanosecond pulse laser with a wavelength of 1064 nm and pulse width of 12 ns, and they found a qualitative correlation between the shock-wave velocity and pressure: they found that the greater the shock-wave velocity, the greater the pressure [11].…”

Características estruturais e propriedades ópticas de filmes finos nanocristalinos de h-BN

“…É importante ressaltar a presença de oxigênio residual, que irá inserir-se nos filmes como contaminante, fato que será analisado detalhadamente mais adiante. Ademais, é visível a reprodutibilidade e estabilidade do processo, ambas avaliadas de forma qualitativa, uma vez que, para conclusões quantitativas sobre as composições de plasmas, são necessários aparatos experimentais que forneçam resolução temporal e/ou espacial do sistema, além de aparatos auxiliares como uma sonda de Langmuir para medir temperatura e densidade de elétrons [51][52][53][54][55]. Isso se deve às probabilidades para cada transição quântica possível de determinada espécie que varia, além de outros parâmetros, como energia do plasma, temperatura dos elétrons, seção de choque das espécies, fatores que precisam ser considerados na correção dos espectros de emissão para obter uma avalição quantitativa [48][49][50].…”