Design of a beam line for simultaneous dual-beam ion implantation

For over 50 years, various ion beam facilities have been utilized to simulate the irradiation effect of neutrons on relevant nuclear materials. However, due to the limitation of single ion beam irradiation, the injection of H-2(+) and He+ into the sample coaxially is necessary to observe the synergy of hydrogen and helium displacement damage. This study presents a beam line design that is capable of separating ions with different charge mass ratios, screening out unwanted particles, and finally combining the separated beams again. Through this design, H+, H-2(+), and He+ beams can be completely separated with an axis deviation of less than 0.5 mm after beam combination. Furthermore, the proportion of H-2(+) and He+ can be adjusted by regulating the inlet air of the ion source, down to the accuracy of a single ion. An accelerating tube is employed to adjust the energy of implanted ions within 10-50 keV. This device also has the capability to efficiently transmit a single type of ion while filtering out extraneous ions (such as O+ beam). The fine-beam optical design not only makes it easy to adjust beam parameters but also eliminates the need for a high-precision power supply. The goal of this work is to have an analytical tool to understand the effect of each electromagnetic component on the ion trajectories.