An apparatus for merging a low energy electron flow into a high energy electron flow may include: a high energy electron path for accommodating the high energy electron flow; and a plurality of magnetic elements arranged to guide the low energy electron flow through a chicane presenting a path having a first end and a second end. The path intersects the high energy electron path at the second end. The path has a plurality of turns and path segments intermediate the first and second ends. Respective adjacent path segments intersect at each respective turn. The path establishes a respective bend radius and subtends a respective path angle between respective adjacent path segments at each respective turn. Each respective path angle is maximized within predetermined path angle limits. Each respective bend radius is minimized within predetermined bend radius limits.