New LLRF capabilities and beam results for the second year of ELENA’s commissioning

CERN’s Extra Low ENergy Antiproton (ELENA) ring underwent its second full year of beam commissioning in 2018. The commissioning was very successful, although delayed by recurrent lack of beam availability from the H- source as well as from the Antiproton Decelerator (AD) ring. Major achievements of the ELENA commissioning in 2018 included the deployment of all required features in its Low-Level RF (LLRF) system, the commissioning of the electron cooler and the delivery of extracted beam to the Gravitational Behaviour of Antihydrogen at Rest (GBAR) experiment. This note describes the LLRF functionalities deployed during the 2018 ELENA run together with the main beam results obtained and some problems encountered. Remaining tasks to be integrated and validated are also summarised. This note is not only a general documentation of what has been achieved. First and foremost this note is intended to contribute in the training of LLRF experts and OP / ABP colleagues, in view of the future ELENA LLRF operation. Owing to the similarities between ELENA and the AD machine, this note will also be useful for the development and commissioning of the post-Long Shutdown 2 (LS2) AD LLRF, based upon the same system.