Investigation of plasma produced by electron pulse ablation

Abstract

Short electron pulses with high energy are a very promising tool for the controlled ablation and deposition of materials. The plasmas induced by the electron beam irradiation are distinguished by their high degree of ionization and excitation. A source for pulsed electron beam is the channel spark device. It delivers pulsed high current and self-focused electron beams (about 15 keV, 1 kA, 100 ns). For deposition technology, the plasma beam is the decisive element of the pulsed vapor deposition (PVD) equipment. Hence, the characteristics of the plasma and its dependence on the primary irradiation are of principal importance. The development of the plasma has been characterized by the emitted optical radiation, spectral resolved. Since the energy of the electron beam is not constant during the pulse, the plasma of the channel spark shows strong variations in its temperature and degree of ionization. In the following, spectral-resolved snapshot pictures of the plasma are represented. Cons idering the short pulse times and the small dimensions, a special high-speed camera combining high-temporal, high-spatial and high-spectral resolution has been applied

Modeling of Plasma Expansion during Pulsed Electron Beam Ablation of Graphite

“…This is in accordance with our calculations, whereby the average electron density is ~10 23 m -3 . It has been found that the average temperature of the plasma varies from 1 eV to 1.25 eV [15,16]. The results based on our calculations indicate that the plasma temperature is ~1 eV, which is in quantitative agreement with the experimental data.…”

“…Experimental results have reported electron density values in the range of 10 22 -10 23 m -3 [15][16][17]. This is in accordance with our calculations, whereby the average electron density is ~10 23 m -3 .…”

“…Towards the end of the pulse, the shock waves seem to blend together resulting in a broader shock wave, as depicted in Figure 1 at t = 80 ns, 100 ns. The plasma temperature slightly increases due to the polyenergetic nature of the electron beam [14,15]. Plasma velocity profile calculated for various time intervals is shown in Figure 2.…”

“…In order to assess the model, some of the calculated variables from the current model have been compared with experimental data available in the literature for plasma induced during PEBA [15][16][17]. Experimental results have reported electron density values in the range of 10 22 -10 23 m -3 [15][16][17].…”

Nanostructure of Materials and Corrosion Resistance

“…Of course, there are many industrial processes that require a higher level of resistance to corrosion. Carburizing has been applied to austenitic stainless steel to promote increased wear and corrosion resistance [93]. Nanometricsized carbide-based crystallites have been synthesized successfully through the pulsed nanocrystalline plasma electrolytic carburizing method on the surface of 316 austenitic stainless steel [94].…”