Timoshenko, M.V. Borin, V.M. Dorokhov, V.L. Meshkov, O.I. Rogovsky, Yu. A. Shwartz, D.B. Zharinov, Yu.M. JACoW Publishing Geneva, Switzerland 978-3-95450-201-1 10.18429/JACoW-IBIC2018-WEPA18 English 410-414 WEPA18 electron synchrotron positron collider injection Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-IBIC2018-WEPA18 http://jacow.org/ibic2018/papers/wepa18.pdf The comprehensive development of beam longitudinal profile measurement systems based on stroboscopic optical dissector has started at VEPP-2000 electron-positron collider complex. The dissector was setted and commissioned at booster ring BEP that was deeply upgraded (2013-2015) to achieve top energy of 1 GeV. Bunch lengthening with current was studied at BEP with its new RF-cavity. In addition the method of synchrotron frequency measurement by dissector was applied. After dissector checkouts at BEP the similar studies were carried out with a single beam at VEPP-2000 storage ring in parallel with streak-camera measurements. Good agreement of results was observed. Series of single-turn longitudinal and vertical bunch profiles snapshots was made by streak-camera with respect to delay after counter beam injection. The unexpected longitudinal beam dynamics was observed for intensities above the beam-beam threshold. These studies together with beam-beam coherent oscillations spectra seen by pickups are of a great interest for understanding of flip-flop phenomenon which establish a fundamental luminosity limit at VEPP-2000 operating with round beams.