Speaker
Description
The neutron time-of-flight facility n_TOF at CERN has been producing relevant nuclear data for science and technology since 2001. In particular, neutron-induced cross sections have been reported on more than 100 reactions, so far. Among them, the $^{235}$U(n,f) cross section was deeply studied [1,2] in different energy regions and using several detector concepts, for instance Parallel Plate Avalanche Counter (including the measurement of angular distribution of the fission fragments), Micromegas, silicon solid state detectors and Fast Ionization Chambers. Moreover, ratios to $^{238}$U(n,f) [3], and more recently to neutron-proton elastic scattering [4,5,6] cross sections were measured at high energy (neutron energy above 20 MeV) as well as ratios to $^{10}$B(n,$\alpha$) and $^{6}$Li(n,t) cross sections in the epithermal region [7,8]. Other features of the fission process were also investigated as for instance the prompt fission $\alpha$ spectra and multiplicities using the SpecTrometer for Exotic Fission Fragments [9,10]; and the capture-over-fission ratio combining (n,$\gamma$) and fission detectors [11].
In this contribution, I will present an overview of the experimental activities related to 235U, with a particular focus on cross section ratios, most recent results and comparisons with data in the literature and evaluations.
[1] C. Paradela et al., EPJ Web Conf. 111 (2016) 02003
[2] E. Leal-Cidoncha et al., EPJ Web Conf. 111 (2016) 10002
[3] C. Paradela et al., Phys. Rev. C 91 (2015) 024602
[4] A. Manna et al., EPJ Web Conf. 239 (2020) 01008
[5] E. Pirovano, A. Manna et al., Measurement of the neutron-induced fission cross section of U-235 relative to neutron-proton elastic scattering at CERN-n_TOF: results from 20 MeV to 200 MeV, submitted to ND2022
[6] A. Manna, E. Pirovano et al., Measurement of the $^{235}$U(n,f) cross section relative to n-p scattering up to 500 MeV at the n_TOF facility at CERN, submitted to ND2022
[7] S. Amaducci et al., Eur. Phys. J. A 55 (2019) 120
[8] V. Michalopoulou et al., Measurement of the $^{235}$U(n,f) cross section relative to the $^{10}$B(n,$\alpha$) reaction with Micromegas detectors at the CERN n_TOF facility: first results, submitted to ND2022
[9] G. Smith et al., CERN-INTC-2014-004, INTC-P-405 http://cds.cern.ch/record/1642581
[10] T. Wright et al., Measurement of the prompt fission gamma-rays from $^{235}$U(n,f)thermal with STEFF, submitted to ND2022
[11] J. Balibrea-Correa et al., Phys. Rev. C 102 (2020) 044615