10th Workshop on Nuclear Level Density and Gamma Strength

Neutron transmission as a surrogate to tightly constrain neutron capture rates on radionuclides

21 May 2026, 11:10

30m

Auditorium 1 (Helga Engs Hus)

Oral Midday Session

Speaker

Thanos Stamatopoulos (Los Alamos National Laboratory)

Description

Th. Stamatopoulos, P. Koehler, A. Cooper, A. Couture, B. DiGiovine, T. Morrow, E. Renner, J. Svoboda

Los Alamos National Laboratory, 87545, NM, USA

With very few exceptions, direct measurements of neutron capture rates on radionuclides have not been possible. A number of indirect methods have been pursued such as the surrogate method [1], the γ-ray strength function method [2,3], the Oslo method [4-7] and the β-Oslo method [8]. Substantial effort has been devoted to quantifying the usually large systematic errors that accompany the results from these techniques. A new instrument has been recently developed at the Los Alamos Neutron Science CEnter (LANSCE) to provide more accurate data on several radionuclides relevant to nuclear criticality safety, radiochemical diagnostics, astrophysics, nuclear forensics and nuclear security, by measuring the transmission of neutrons through radioactive samples and studying resonance properties. The Device for Indirect Capture on Radionuclides (DICER) [9-11] and associated radionuclide production at the Isotope Production Facility (IPF) [12, 13], both at LANSCE, as well radioactive sample fabrication, have been under development the last few years. A description of the apparatus, technique and some published data [14, 15] will be presented.

References
1. J. E. Escher et al., Phys. Rev. Lett. 121, 052501 (2018)
2. H. Utsunomiya et al., Phys. Rev. C 82, 064610 (2010)
3. H. Utsunomiya et al., Phys. Rev. C 88, 015805 (2013)
4. M. Guttormsen et al., Nucl. Instrum. Meth. A, 374 (3) (1996)
5. M. Guttormsen et al., Nucl. Instrum. Meth. A, 255 (3) (1987)
6. A. Schiller et al., Nucl. Instrum. Meth. A, 447 (3) (2000)
7. A. C. Larsen et al., Phys. Rev. C 83, 034315 (2011)
8. A. Spyrou et al., Phys. Rev. Lett. 113, 232502 (2014)
9. P.E. Koehler, Springer Proceedings in Physics, 254 (2021) p. 187
10. P.E Koehler, LA-UR-18-22995 (2018)
11. A. Stamatopoulos et al., Nucl. Instrum. Meth. A, 1025 (2022) 166166
12. K.F. Johnson et al., LA-UR-04-4570 (2004)
13. https://lansce.lanl.gov/facilities/ipf/index.php
14. A. Stamatopoulos et al., Phys. Rev. Lett. 134, 112702 (2025)
15. A. Stamatopoulos et al., Phys. Rev. C 111 034613 (2025)

Presentation materials

Oslo2026_Thanos_DICER.pptx