The International Linear Collider is a proposed electron-positron linear collider, where the positron beam is generated by undulator radiation hitting a target. The resulting, highly divergent positron beam requires immediate optical matching to improve the luminosity and ensure the success of the intended collision experiments. Here, optical matching refers to the process of capturing particles and making them available for downstream beamline elements like accelerators. In the past, this has been done with sophisticated coils, but more recently the usage of a current-carrying plasma, a so-called plasma lens, has been proposed as an alternative. For the International Linear Collider, idealised particle tracking simulations have already been done in the past with the purpose of finding the optimal plasma lens design with respect to the captured positron yield. The proposed design is conical in shape to accommodate for the large beam divergence [1]. Now further research and development of this design is required, including both experiments with a downscaled prototype set-up as well as corresponding simulations modelling the hydrodynamics of the current-carrying plasma. The accuracy of the latter will benefit greatly from the former. In this work, first preliminary hydrodynamic simulations instil confidence into further endeavours.

Beam-driven plasma-wakefield acceleration is a promising avenue for future accelerators, where a high electric field gradient could reduce the size and cost of a high-energy physics or a photon-science facility. Successful experimental results in recent decades have demonstrated the feasibility of high-gradient acceleration in plasma. However, to meet the demands of current conventional accelerator users in terms of luminosity and brightness, there are more milestones to reach. Preservation of beam quality, high overall energy-transfer efficiency, and high-average-power operation comprise the three major research pillars of FLASHForward: a plasma-wakefield-acceleration research facility at DESY. Recent results from FLASHForward include per-mille-level energy-spread preservation; high energy-transfer efficiency of 42% from the wake to the accelerating bunch; and the in-principle operation of plasma accelerators at O(10 MHz) inter-bunch repetition rates — all demonstrating promise to shrink the footprint of future accelerator facilities without a loss in functionality or efficacy. In this submission an overview of the facility, recent results, and future outlook are presented.