Preliminary results on the U-233 α-ratio measurement at n_TOF Bacak, M. Porras Sánchez, José Ignacio Praena Rodríguez, Antonio Javier TOF Collaboration This work was partially supported by the French NEEDS/NACRE Project and by the European Commission within HORIZON2020 via the EURATOM Project EUFRAT. The authors would like to acknowledge more specifically JRC Geel for targets preparation and for providing full support for a first test measurement of the fission chamber at GELINA. U-233 is the fissile nuclei in the Th-U fuel cycle with a particularily small neutron capture cross setion which is on average about one order of magnitude lower than its fission cross section. Hence, the measurement of the U-233(n,gamma) cross section relies on a method to accurately distinguish between capture and fission gamma-rays. A measurement of the U-233 alpha-ratio has been performed at the n_TOF facility at CERN using a so-called fission tagging setup, coupling nTOF 's Total Absorption Calorimeter with a novel fission chamber to tag the fission gamma-rays. The experimental setup is described and essential parts of the analysis are discussed. Finally, a preliminary U-233 alpha-ratio is presented. 2021-05-04T10:33:55Z 2021-05-04T10:33:55Z 2020-09-30 info:eu-repo/semantics/conferenceObject EPJ Web of Conferences 239, 01043 (2020). [https://doi.org/10.1051/epjconf/202023901043] http://hdl.handle.net/10481/68305 10.1051/epjconf/202023901043 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España EDP Sciences