Cocktail beams, composed of multiple ion species with tailored energy and composition, have emerged as a transformative tool for simulating the synergistic irradiation effects experienced by structural materials in advanced nuclear reactors. This study demonstrates the development of cocktail ion beams at the Low Energy high-intensity heavy ion Accelerator Facility (LEAF), leveraging a fourth-generation superconducting ECR ion source (FECR) and energy modulation systems to generate high-intensity, low-energy-spread beams. Key innovations include a drift tube linac (DTL) and rebunchers, enabling precise energy tuning to align ion penetration depths. To validate the radiation-induced damage characteristics of mixed-ion beams, irradiation responses of monocrystalline copper were systematically compared across different irradiation modalities. The analysis reveals that simultaneous cocktail beam exposure induces markedly distinct microstructural evolution compared to sequential irradiation (e.g., Fe→He or He→Fe) and single-ion (e.g., Fe or He) irradiation protocols under equivalent displacement damage conditions.

Production of 0.5~1.0 emA highly charged heavy ion beams has been requested by worldwide next generation heavy ion facilities, but remains big challenge to the community. Regarded as the most powerful machine to produce high intensity heavy ion beams, ECR ion sources have been used by most of the heavy ion accelerator facilities in the world, which have also greatly boosted their continuous development over the years. Even after more than 50 years since the first prototype ECR ion source was demonstrated, it still retains its vitality in terms of extracted ion beam intensities and charge states. This paper will present the latest progresses of worldwide high performance ECR ion sources. The main contents will focus on new ion source development, high performance operation, new technology research and the perspectives on high beam intensity operation for heavy ion accelerators.