Speaker
Description
A good understanding of Neutron-induced reactions on niobium are important for modeling radiation damage in superconducting magnets used in fusion energy systems and for interpreting archival radiochemical data for national security[1][2]. In order to constrain model parameters used in evaluation, correlated measurements of outgoing neutrons and gammas were collected using the Gamma Energy Neutron Energy Spectrometer for Inelastic Scattering (GENESIS) [3]. A 23 MeV deuteron beam was impinged onto a carbon target to generate a broad energy neutron beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory[4]. A natural Nb target was positioned at the center of the GENESIS array located 7 m downstream from the carbon breakup target. At the time of the experiment GENESIS consisted of 26 liquid organic scintillators for neutron detections and 3 high purity germanium detectors for gamma detection.
This talk will provide an overview of the analysis method using collected neutron and gamma data for reaction model optimization. It will also describe the method used to reproduce the observables measured in the experiment using a characterized array response and a reaction modeling code. The Hauser-Feshbach code CoH3 was used for reaction modeling[5]. The modeling process was applied iteratively in order to provide a set of optimized reaction model parameters in a similar manner to the nuclear data evaluation process but using only a single data set used to constrain several reaction channels.
[1] D. R. Nethaway. “THE 93Nb(n,2n) 92m92Nb CROSS SECTION”. In: Journal of L Inorganic and Nuclear Chemistry. (1977).
[2] D. R. Nethaway and M. G. Mustafa. “Measured Data Used in the Watusi Cross-Section Sets”. In: National Technical Information Service
(1999).
[3] J.M. Gordon et al. “GENESIS: Gamma Energy Neutron Energy Spectrometer for Inelastic Scattering”. In: Nuclear Instruments and Methods
in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1061 (2024), p. 169120. issn: 0168-9002. doi:
https://doi.org/10.1016/j.nima.2024.169120. url: https://www.sciencedirect.com/science/article/pii/S0168900224000469.
[4] J. T. Morrell et al. “Secondary neutron production from thick target deuteron breakup”. In: Phys. Rev. C 108 (2 Aug. 2023), p. 024616.
doi: 10.1103/PhysRevC.108.024616. url: https://link.aps.org/doi/10.1103/PhysRevC.108.024616.
[5] T. Kawano. “CoH3: The Coupled-Channels and Hauser-Feshbach Code”. eng. In: Compound-Nuclear Reactions. Springer Proceedings in
Physics. Cham: Springer International Publishing, 2020, pp. 27–34. isbn: 3030580814. doi: 10.1007/978-3-030-58082-7_3.