Single Free-Falling Droplet of Liquid Metal as a Source of Directional Terahertz Radiation

International audienc

Shaping and controlled fragmentation of liquid metal droplets through cavitation

Targeting micrometer sized metal droplets with near-infrared sub-picosecond laser pulses generates intense stress-confined acoustic waves within the droplet. Spherical focusing amplifies their pressures. The rarefaction wave nucleates cavitation at the center of the droplet, which explosively expands with a repeatable fragmentation scenario resulting into high-speed jetting. We predict the number of jets as a function of the laser energy by coupling the cavitation bubble dynamics with Rayleigh-Taylor instabilities. This provides a path to control cavitation and droplet shaping of liquid metals in particular for their use as targets in extreme-UV light sources.Published versio

Renewable single-walled carbon nanotube membranes for extreme ultraviolet pellicle applications

Publisher Copyright: © 2022 The AuthorsWe propose a facile, cost-efficient, environmentally friendly, and scalable process to renew single-walled carbon nanotube membranes serving as extreme ultraviolet (EUV) protective pellicles. The method comprises of high-temperature treatment of the membrane by Joule (resistive) heating at temperatures higher than 1000 °C and pressure below 0.3 Pa. Using model Sn aerosol nanoparticles, the primary contaminant from extreme ultraviolet light sources, we demonstrate the proposed method to clean the membrane with the power consumption as low as 20 W/cm2. We show the proposed method to cause no harm to carbon nanotube structure, opening a route towards multiple membrane renovation. We confirm the applicability of the approach using in situ deposition from the semi-industrial EUV light source and subsequent Sn-based contaminant removal, which restores the EUV-UV-vis-NIR transmittance of the film and, therefore, the light source performance. The proposed method supports pulse-cycling opening an avenue for enhanced protection of the lithography mask and stable performance of the EUV light source. Additionally, the approach suits other composite contaminants based on such species as Pb, In, Sb, etc.Peer reviewe