Structured targets at high-repetition rates for high-intensity laser-plasma interactions

The use of structured targets to improve specific experimental outcomes has been robustly studied in simulations and is being used more frequently for experiments as technology improves. These structures, including microtubes, cones, cone-wires, and curved targets, have proven useful for many applications but are limited in repetition rate due to the precision alignment required and high cost per target. With the rise of high repetition rate, ultra-intense laser systems that can operate above 100 Hz, there comes a need for solid density structured targets that can operate with these systems. In line with our previous work of using ethylene glycol sheet targets that can be 100s of nanometers thick that regenerate as the liquid flows, we demonstrate the generation of a dynamically shaped structured target that can be formed from these sheets after the irradiation of a 10¹⁶ Wcm^-2 short pulse laser. The structured target evolves over microseconds, forming a hollow channel, a cone, a cone-wire, and a curved surface with a wire as it evolves in time. The target can be implemented in a relativistic laser-plasma interaction by selecting the timing delay between a target shaping prepulse and a ultra-high intensity pulse, where the timing delay will determine the structure of the target when the main pulse arrives. The structures are highly repeatable in shape and position, operate above kHz repetition rates, and are very low cost, opening a path to structured target interactions at high repetition rates.