Transparent damping wiggler for low-energy storage rings

Abstract The strong damping wiggler (DW) has the potential to enhance the radiation of the electron beam and reduce the damping time. However, the DW with a strong magnetic field produces a strong focusing effect in the vertical plane, which generates a strong perturbation to the linear optics of the storage ring. In some cases, this can even lead to the absence of a periodic solution, which is more prevalent in low-energy storage rings. This paper presents an initial investigation of two distinct DW structures. In particular, the transparent DW has been observed to satisfy the I transformation, thereby enabling equivalent focusing in both the horizontal and vertical planes. This ensures that the linear optics of the storage ring remain undisturbed and that a number of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>π</mml:mi> </mml:math> nodes between sectors of the DW can cancel out nonlinearities from each other. Furthermore, this paper presents an example of a low-energy electron storage ring design based on the transparent DW that demonstrates the excellent performance of the transparent DW. This DW structure, which can be readily employed in a damping ring for collider, would significantly improve its performance.