Pang, C.G. Bambade, P. Di Carlo, S. Funakoshi, Y. Jehanno, D. Kubytskyi, V. Peinaud, Y. Rimbault, C. Uehara, S. JACoW Publishing Geneva, Switzerland 978-3-95450-201-1 10.18429/JACoW-IBIC2018-MOPA13 English 51-56 MOPA13 luminosity MMI detector feedback monitoring Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-IBIC2018-MOPA13 http://jacow.org/ibic2018/papers/mopa13.pdf LumiBelle2 is a fast luminosity monitoring system prepared for SuperKEKB. It uses sCVD diamond detectors placed in both the electron and positron rings to measure the Bhabha scattering process at vanishing scattering angle. Two types of online luminosity signals are provided, a Train-Integrated-Luminosity at 1 kHz as input to the dithering feedback system used to maintain optimum overlap between the colliding beams in horizontal plane, and Bunch-Integrated-Luminosities at about 1 Hz to check for variations along the bunch trains. Individual beam sizes and offsets can also be determined from collision scanning. This paper will describe the design of LumiBelle2 and report on its performance during the Phase-2 commissioning of SuperKEKB.