Kick-and-cancel injection scheme for the Diamond-II storage ring

The Diamond-II storage ring upgrade will provide users with 1–2 orders of magnitude increase in brightness over the existing Diamond facility, as well as double the number of straight sections to allow for the installation of additional beamlines. A key performance requirement for the upgrade will be to provide a quasitransparent top-up injection scheme. The ring was originally designed to use a single-bunch aperture sharing injection scheme, in which short stripline kickers are used to kick the injected bunch into the storage ring’s dynamic aperture, while the kick remains weak enough to avoid displacing the existing stored bunch outside the acceptance. This scheme has been modified to implement a kick-and-cancel method to place the stored bunch back on axis and leave only the injected bunch to oscillate. The kicker power supplies are thus required to provide a double pulse with a few-microsecond pulse spacing. This new method is expected to significantly improve the transparency of the injection process and reduce the recovery time for the targeted bunch, along with minimizing the transverse wakefield effects and any interactions with the transverse multibunch feedback and harmonic cavity.