Measurement of the 234U(n,f) cross section in the energy range between 14.8 and 17.8 MeV using Micromegas detectors


Published: Apr 17, 2020
Keywords:
234U(n f) fission cross section Micromegas detectors
Antigoni Kalamara
http://orcid.org/0000-0003-4748-7824
S. Chasapogloou
V. Michalopoulou
A. Stamatopoulos
Z. Eleme
M. Kokkoris
A. Lagoyannis
N. Patronis
R. Vlastou
Abstract

Neutron induced fission cross sections of actinides present special interest, since they lead to the design optimization of new generation reactors (Generation IV) as well as Accelerator Driven Systems (ADS). In the present work, the 234U(n,f) cross section was measured for which only a few available discrepant data exist in literature leading to poor evaluations. More specifically, four irradiations were performed at the 5.5 MV Tandem Accelerator Laboratory of NCSR “Demokritos” using quasi-monoenergetic neutrons produced by the 3H(d,n)4He reaction in the 14.8-19.2 MeV energy range. The 234U(n,f) cross section was measured relatively to the 235U(n,f) and 238U(n,f) reference ones and in order to perform the in-beam measurements for each of the actinide targets (234U, 238U, 235U), a Micromegas detector was used to record the fission fragments. The target-detector pairs were placed in an Al chamber filled with a Ar:CO2 (in 80:20 volume fraction) gas mixture at atmospheric pressure and temperature. The efficiency of the Micromegas detectors was estimated by Monte-Carlo simulations using the GEF and FLUKA codes. In addition, a detailed study of the neutron energy spectra was carried out by coupling both NeuSDesc and MCNP5 codes in order to take into account and correct for the contribution of low energy parasitic neutrons in the fission yields.

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References
NEA, Accelerator-driven Systems (ADS) and Fast Reactors (FR) in advanced nuclear fuel Cycles, Technical Report (Nuclear Energy Agency of the OECD, NEA, 2002).
https://www.gen-4.org, Gen-IV International Forum.
F. Tovesson, A. Laptev and T. S. Hill, Nuclear Science and Engineering, 178, 57-65 (2014).
D. Karadimos and the n_TOF Collaboration, Phys. Rev. C, 89, 044606 (2014).
C. Paradela and the n_TOF Collaboration, Phys. Rev. C, 82, 034601 (2010).
Manabe et al.,Technology Reports of the Tohoku University, 52, 97-126 (1988).
J. W. Meadows, Annals of Nuclear Energy, 15, 421-429 (1988).
P. H. White and G. P. Warner, Journal of Nuclear Energy, 21, 671-679 (1967).
R. Babcock, Technical Report, Bettis Atomic Power Lab., Westinghouse, Pittsburgh, PA, USA (1961).
A. Tsinganis et al., EPJ Web of Conferences, 146, 04035 (2017).
A. Stamatopoulos et al., Eur. Phys. J. A, 54:7 (2018).
E. Birgerssone and G. Lovestam , JRC Scientific and Technical Reports (2007).
MCNP-A General Monte Carlo N-ParticleTransport Code, version 5, X-5 Monte Carlo team (2003), LA-UR-03-1987, LA-CP-03-0245 and LA-CP-03-0284.
ENDF, URL: https://doi.org/10.1016/j.nds. 2011.11.002
K.H. Schmidt et al., Nucl. Data Sheets 131, 107 (2016).
A. Ferrari et al., FLUKA: A multi-particle transport code (program version 2005) (CERN, Geneva, 2005) cds.cern.ch/record/898301.