Liu, C. Fedotov, A.V. Kewisch, J. Minty, M.G. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-WEPOB68 English 1045-1047 WEPOB68 ion emittance electron simulation space-charge Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOB68 https://jacow.org/napac2016/papers/wepob68.pdf To improve the luminosity of beam energy scan of low energy Au-Au collision, a electron machine is under con- struction to cool ion beams in both RHIC rings with pulsed electron beam. Over the course of the project, a multi- slit device is needed to characterize the transverse beam emittance of three energies, 0.4, 1.6 and 2.6 MeV. This re- port shows the optimization and compromise of the design, which include the slit width, slit spacing, and drift space from the multi-slit to the downstream profile monitor.