Marqversen, O. Alves, D. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-241-7 10.18429/JACoW-IBIC2022-TUP30 English 296-299 proton simulation feedback antiproton pick-up Contribution to a conference proceedings 2022 2022-12 https://doi.org/10.18429/JACoW-IBIC2022-TUP30 https://jacow.org/ibic2022/papers/tup30.pdf A bunched beam intensity measurement system for the CERN Extra Low ENergy Antiproton (ELENA) ring, using a cylindrical shoe-box electrostatic pick-up from the existing orbit system [1], is presented. The system has been developed to measure very challenging beam cur-rents, as low as 200nA corresponding to intensities of the order of 10⁷ antiprotons circulating with a relativistic beta of the order of 10-2. In this work we derive and show that the turn-by-turn beam intensity is proportional to the baseline of the sum signal and that, despite the AC-coupling of the system, the installed front-end electronics, based on a charge amplifier, not only guarantees the preservation of the bunch shape (up to a few tens of MHz), but also allows for an absolute calibration of the system. In addition, the linearity of the intensity measurements and their inde-pendence with respect to average beam position is evalu-ated using a standard electromagnetic simulation tool. Finally, experimental measurements throughout typical antiproton deceleration cycles are presented and their accuracy and precision are discussed.