Thieberger, P. Altinbas, Z. Carlson, C. Chasman, C. Costanzo, M.R. Degen, C. Drees, K.A. Fischer, W. Gassner, D.M. Gu, X. Hamdi, K. Hock, J. Luo, Y. Marusic, A. Miller, T.A. Minty, M.G. Montag, C. Pikin, A.I. White, S.M. High Energy Coulomb Scattered Electrons Detected in Air Used as the Main Beam Overlap Diagnostics for Tuning the RHIC Electron Lenses JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-MOA3IO01 English 20-24 MOA3IO01 ion electron proton alignment detector Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-MOA3IO01 https://jacow.org/napac2016/papers/moa3io01.pdf A new type of electron-ion beam overlap monitor has been developed for the RHIC electron lenses. Low energy electrons acquire high energies in small impact parameter Coulomb scattering collisions with relativistic ions. Such electrons can traverse thin vacuum windows and be conveniently detected in air. Counting rates are maximized to optimize beam overlap. Operational experience with the electron backscattering detectors during the 2015 p-p RHIC run will be presented. Other possible real-time non-invasive beam-diagnostic applications of high energy Coulomb-scattered electrons will be briefly discussed.