First results of the 230Th(n,f) cross section measurements at the CERN n_TOF facility

V Michalopoulou,M Krtiička,J Perkowski,C Petrone,F Gunsing,M Caamaño,E Mendoza,F Mingrone,A Musumarra,V Alcayne,S Heinitz,A Oprea,R Vlastou,D Macina,P M Milazzo,B Femández-Domíngez,U Jiri,A Gawlik,P J Woods,P Torres-Sánchez,M A Millán-Callado,M Sabaté-Gilarte,E Pirovano,D G Jenkins,A Tsinganis,S Amaducci,P Vaz,E Chiaveri,S Bennett,A Manna,N Patronis,V Furman,M Dietz,M Kokkoris,E Dupont,E Jericha,G Tagliente,Y Kadi,C Rubbia,F Calviño,V Variale,L A Damone,Q Ducasse,I Ferro-Gonçalves,O Aberle,A Sekhar,Z Eleme,L Audouin,F Ogállar,M Bacak,I Ladarescu,A Pavlik,F Käppeler,A Stamatopoulos,S Valenta,M Mastromarco,A Masi,A Negret,A Casanovas,E Berthoumieux,J Andrzejewski,G Vannini,M Barbagallo,T Martínez,R Dressler,A Mazzone,D Kurtulgil,L Caballero,I Porras,A Kimura,J Praena,A Saxena,B Thomas,P Finocchiaro,J Heyse,A Mengoni,P J Davies,D Bosnar,S Gilardoni,A Junghans,D Schumann,K Göbel,A Wallner,P Schillebeeckx,F Cerutti,M Busso,R Garg,M Calviani,N Colonna,P Sprung,A Ferrari,I Durán,C Guerrero,D Rochman,L Piersanti,C Massimi,D Ramos Doval,I Knapová,A Ventura,V Vlachoudis,R Reifarth,L Tassan‐Got ,V Babiano-Suárez ,A Tarifeño-Saldivia ,S J Lonsdale ,J Moreno-Soto ,Yu N Kopatch ,J Lerendegui-Marco ,G Cortés ,E González‐Romero ,C Lederer-Woods ,E A Maugeri ,C Domingo‐Pardo ,S Urlaß ,T Wright ,N V Sosnin ,J L Taín ,Andrew Smith ,M A Cortés‐Giraldo ,J Quesada ,D Cano‐Ott ,A Brown ,L Coséntino ,Μ Diakaki ,P Mastinu ,D Vescovi,P Žugec,S Cristallo

doi:10.1051/epjconf/202023905004

Abstract

The study of neutron-induced reactions on actinides is of considerable importance for the design of advanced nuclear systems and alternative fuel cycles. Specifically, 230Th is produced from the α-decay of 234U as a byproduct of the 232Th/233U fuel cycle, thus the accurate knowledge of its fission cross section is strongly required. However, few experimental datasets exist in literature with large deviations among them, covering the energy range between 0.2 to 25 MeV. In addition, the study of the 230Th(n,f) cross-section is of great interest in the research on the fission process related to the structure of the fission barriers. Previous measurements have revealed a large resonance at En=715 keV and additional fine structures, but with high discrepancies among the cross-section values of these measurements. This contribution presents preliminary results of the 230Th(n,f) cross-section measurements at the CERN n_TOF facility. The high purity targets of the natural, but very rare isotope 230Th, were produced at JRC-Geel in Belgium. The measurements were performed at both experimental areas (EAR-1 and EAR-2) of the n_TOF facility, covering a very broad energy range from thermal up to at least 100 MeV. The experimental setup was based on Micromegas detectors with the 235U(n,f) and 238U(n,f) reaction cross-sections used as reference.

Highlights

The Th/U fuel cycle has several advantages concerning radioactive waste management and non-proliferation, compared with the conventional U-Pu fuel cycle [1]
The measurement was performed at the experimental areas EAR-1 and EAR-2 of the CERN n_TOF facility
Experimental area EAR-1 offers better neutron energy resolution combined with the capability to reach higher neutron energies, while experimental area EAR-2 offers a higher neutron flux [4]

Summary

Introduction

The Th/U fuel cycle has several advantages concerning radioactive waste management and non-proliferation, compared with the conventional U-Pu fuel cycle [1]. In order to achieve improved design calculations for thorium based reactors, the determination of neutron induced reaction cross-sections on isotopes of thorium is required. The 230Th isotope is produced from the αdecay of 234U as a byproduct of the 232Th/233U fuel cycle. Regarding 230Th(n,f) cross-section, the existing experimental datasets cover the energy range between 0.2 to 25 MeV with large deviations among them. Interesting structures appear in the cross section of this isotope at the fission barrier, giving insight to the fission potential wells. In this context, the 230Th(n,f) cross-section was measured at the CERN n_TOF facility, with the aim of covering with high accuracy data over a broad energy range from thermal up to at least 100 MeV

Methods

Results

Conclusion