Generation of kHz-rate complex-structured liquid targets for relativistic laser–plasma interactions

With the rise of high repetition rate ultra-intense laser systems, there is a need for solid density targets to study relativistic laser–plasma interactions that can operate at the same repetition rate. Flowing liquid targets are attractive because they are self-replenished, debris free, cost effective and easy to use. Liquid targets have been used for high-repetition rate (up to kHz rate) generation of electrons, protons, x rays, and neutrons by our group and elsewhere. In this Letter, we demonstrate a kHz-rate generation of a variety of dynamically shaped complex-structured targets from the interaction of a 1016 W/cm2 focused laser pulse with a submicrometer liquid sheet. The repeatable structured target evolves over microseconds, forming different shapes, such as a hollow channel, a cone, a cone-wire, and a curved surface with a wire. Based on a particle-in-cell simulation, we show that with a cone-wire target, the kHz-rate laser–target interaction could enable the statistical study of warm-dense matter generation that may be useful as a high flux x-ray source. Each stage of the target evolution provides a unique target geometry for ultra-intense laser plasma interaction with numerous potential applications, such as pulsed secondary source generation for high-resolution imaging.