Neutron capture cross section of Mn53 from irradiation with cold and reactor neutrons

Abstract

The neutron capture cross section of 53 Mn was measured with cold and reactor neutrons by the activation method, relative to the well-known cross section of 59 Co. Three targets containing a total of ≈10 18 atoms 53 Mn in the form of chloride salt were prepared using a stock solution obtained from activated accelerator waste in the course of the ERAWAST initiative at Paul Scherrer Institute, Switzerland (PSI). Natural cobalt salt was added to the sample material as an internal neutron flux monitor. The total numbers of 53 Mn and 59 Co atoms in the target were deduced via mass spectrometric measurements at PSI. Cold-neutron activation was carried out at the ICON beamline at PSI. Reactor activation was performed at the LVR-15 research reactor of Research Centrě Rež in a well-moderated neutron field of an outer reactor channel. The thermal-neutron capture cross section and the resonance integral were determined by the cadmium ratio method. The induced activities of 54 Mn and 60 Co were quantified by high-resolution γ-ray spectrometry. The obtained thermal-neutron capture cross section of 76.5 ± 1.4 b agrees well with previously reported results. The uncertainty of this value could be reduced by almost an order of magnitude with respect to older measurements and is on a level comparable to stable nuclides. The resonance integral of 43.1 ± 1.2 b was obtained for the real reactor spectrum with epithermal-spectrum shape factor α = 0.025.

Exotic Radionuclides – What are they good for?

“…4, the results for the thermal neutron cross section, measured at the research reactor LVR-15 in Rez (Czech Republic), and for the cold neutrons using the ICON beamline at PSI, reproduce well the values known from literature [36a] with an essentially improved uncertainty. [42] Moreover, it was possible for the first time, using the LiLiT source at SOREQ (Israel), to obtain a Maxwellian Averaged Cross Section (MACS), matching stellar neutron energies of 20-50 keV. [43] The work is completed by measuring the interaction of very cold neutrons at ILL with 53 Mn.…”