CesrTA is a test accelerator facility at Cornell University that has been configured to study physics associated with electron and positron damping rings. Electron cloud effects is a concern for positron beams for such damping rings. The presentation will give an overview of recent measurements and simulation results for CesrTA. The measurement conditions were set up in order to study single bunch phenomena by observing a "Witness bunch" behind a train of positron bunches. The beam size and the turn by turn spectra were obeserved for the witness bunch under different conditions. Simulations were performed under similar conditions using the program CMAD. Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA
