Neutral atomic jet generation by laser ablation of copper targets

Abstract

This work aimed the obtainment of a neutral atomic jet departing from a plume generated by laser ablation of copper targets. A pair of electrodes together with a transducer pressure sensor was used to study the ablated plume charge composition and also to measure the ion extraction from the plasma plume. The neutral beam was produced with this setup and the relative abundance of neutrals in the plasma was measured, it decreases from 30% to 8% when the laser fluence is varied from 20 J/cm(2) to 32 J/cm(2). The necessary voltage to completely remove the ions from the plume varied from 10 V to 230 V in the same fluence range. TOF analysis resulted in center of mass velocities between 3.4 and 4.6 km/s, longitudinal temperature in the range from 1 × 10(4) K to 2.4 × 10(4) K and a Mach number of M = 2.36, calculated using purely hydrodynamic expansion approximation.

Isotope-Selective Laser Ablation Ion-Trap Loading of $\mathbf{^{137}\mathrm{Ba}^+}$ using a $\mathbf{\mathrm{BaCl}_2}$ Target

“…The time-resolved spectroscopy results indicate that plume temperatures from ablating the bariumsalt targets are high, at around 37, 000 K. Most other groups have measured a neutral atom ablation plume temperature of 1, 000 to 10, 000 K [24,33,58], but some have measured similar temperatures as us [58,72]. Our barium-salt target could be exhibiting different plume dynamics, or the contrast may partly be explained by a difference in data analysis.…”

Gold-implanted plasmonic quartz plate as a launch pad for laser-driven photoacoustic microfluidic pumps

“…A clear picture of the formation of a jet by a single pulse has given us strong evidence to disqualify alternative theories for laser-induced pumping or streaming. The possibility of jet by bubble cavitation, laser ablation, or laser-induced forward transfer can be immediately eliminated because no microbubble, no cavitation, and no plume is observed (26–31). Most importantly, all these theories imply that a jet should be launched from the surface of the quartz window; in other words, the fluid near the window surface should have the highest speed.…”

“…Finally, only one cavity is created each time at specific position; multiple cavities will require multiple beams to avoid optical misalignment between a cavity and the laser beam that creates it. It would be convenient to simply coat a quartz plate with Au film by thermal evaporation; however, due to the weak attachment to the substrate, the Au film will be quickly removed by laser ablation or laser-induced forward transfer (5, 28–31). All of the above limitations are overcome by implanting Au into a quartz plate to create a launch pad for long-lasting photoacoustic microfluidic pumps.…”