Short-Period undulators with electrostatic field

Due to strong sextupole corrections, the vertical dynamic aperture of a low-emittance storage ring is rather small. Therefore, in-vacuum short-period undulators can provide a sufficiently high field. In particular, a significant electrostatic field value can be obtained near electrodes. To eliminate the field emission, the high-field surfaces should be at a positive electric potential. In this paper, we consider the feasibility of an undulator using a comb of such electrodes. It is worth noting that a variable-period design may be rather simple for electrostatic undulators.