A comparative study on the characteristics of nanosecond laser ablation zinc and acrylonitrile butadiene styrene targets

Abstract

In this study, the influence of laser energy and pressure on propulsion performance of zinc and acrylonitrile butadiene styrene (ABS) is investigated by impulse measurement, fast exposure images, spectral diagnostics and target ablation. A Q-switched Nd: YAG laser with the wavelength of 1064nm and pulse width of 6 ns is employed. The impulse and coupling coefficient generated by laser ablation ABS are greater than that of Zn, and they exhibit a similar variation trend with pressure. However, at higher pressure levels, the change in impulse versus laser energy is not completely coincident between Zn and ABS samples. The target property plays a significant role in the generation and propagation of plume related to the plasma parameters such as electron density and temperature. The temporal evolution images indicate that the plasma plume of laser-induced Zn presents a faster decay in comparison with that of ABS, which is ascribed to the fact that the gas temperature of ABS is higher than the electron temperature of Zn plasma in the local thermodynamical equilibrium. Also, the electron density is lower for Zn due to the rapid heat diffusion and higher ablation threshold of metal. It is found that the surface absorption is dominant for metal because the ablated crater of Zn performs larger diameter and shallower depth. On the contrary, the shrinkage in diameter but enhancement in depth of crater is observed from ABS surface, and the ablation mass is larger, suggesting the obvious volume absorption for polymer. The results reveal that the target property can engender an important effect on the energy conversion between laser, target and plasma.

Effect of laser wavelength on ablation propulsion and plasma characteristics with acrylonitrile butadiene styrene target

“…Regardless of laser wavelength, the impulse and C m firstly increase, reaching their maximum at the pressure of 150 Torr, and then decline as the pressure continues to decrease. The result is in agreement with our previous work and the influence of pressure on impulse and C m has been analyzed [30,31]. Plasma generation and propagation, which depend on the power densities and absorption mechanisms at different laser wavelengths, are considered to be the key factors for the variation of impulse and C m .…”

“…A schematic diagram of the experimental setup shown in figure 1 is similar to that described in our previous work [30,31]. A Q-switched Nd: YAG laser (Q-smart 850) operating at its fundamental (1064 nm), second (532 nm), and third (355 nm) harmonics is used for target ablation.…”

“…Compared to laser wavelengths of 532 nm and 355 nm, the laser-target interaction is weakened at longer wavelength, leading to the lower impulse and C m at 1064 nm. Furthermore, as previously analyzed, the ablation impulse is dependent on the dynamics and propagation process of plasma plume [30,31,[38][39][40]. Therefore, the time-resolved images are employed to reveal the influence of plume dynamics on impulse and C m caused by laser ablation in the following part.…”

“…In the present work, the impulse and C m generated by laser ablation of acrylonitrile butadiene styrene (ABS) are experimentally investigated as a function of laser wavelength. The ABS target is chosen based on the low thermal conductivity and high latent heat of the polymer, which has been demonstrated to be able to obtain the better propulsion performance compared with that produced by other materials such as zinc, polyvinyl chloride and graphite, etc [4,9,30]. The laser-target interaction is characterized by crater morphology and ablation mass.…”

Experimental Investigation on Morphological Characteristics and Propulsion Performance of Typical Metals Ablated with Multipulse Nanosecond Laser

“…Li [15] demonstrated the high propulsion efficiency of metal microspheres by irradiating stainless steel microspheres with the nanosecond laser output from optical fibers. Xu [16] analyzed the impact of different laser energies and pressures on the propulsion performance of zinc from the perspective of the impulse.…”