Marroncle, J. Abbon, P. Akagi, T. Bellan, L. Bolzon, B. Cara, P. Chaminade, T. Chauvin, N. Chel, S. Comunian, M. Denis, J.F. Dzitko, H. Fagotti, E. Gaget, A. García, J.M. Gex, D. Grespan, F. Jiménez-Rey, D. Jokinen, A. Kondo, K. Pisent, A. Rodríguez Páramo, A. Ros, A. Scantamburlo, F. Sugimoto, M. Villamayor, V. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-204-2 10.18429/JACoW-IBIC2019-TUPP006 English 288-292 TUPP006 emittance electron MMI proton rfq Contribution to a conference proceedings 2019 2019-11 https://doi.org/10.18429/JACoW-IBIC2019-TUPP006 http://jacow.org/ibic2019/papers/tupp006.pdf IFMIF (International Fusion Materials Irradiation Fa-cility) is an accelerator-driven neutron source aiming at testing fusion reactor materials. Under the Broader Ap-proach Agreement, a 125 mA / 9 MeV CW deuteron accelerator called LIPAc (Linear IFMIF Prototype Accel-erator) is currently under installation and commissioning at Rokkasho, Japan, to validate the IFMIF accelerator. During the beam commissioning at 5 MeV which started in June 2018, the horizontal and vertical transverse emit-tance of a 2.5 MeV proton beam have been measured downstream of the RFQ for different machine configura-tions. Such measurements were done with an emittance measurement unit composed of slits defining a beamlet of 200 µm width, then of steerers and finally of a SEM grids monitor. In this paper, the process and the system are first described. The secondary electron emission of SEM-Grid wires is then estimated based on measure-ments and results are close to the usual rule of thumb. Finally, emittance measurements are presented and comparisons with beam dynamics simulations show good agreement.