Level structure of 42K from the 41(n, γ) and 41K(d, p) reactions

Thermal neutron capture cross sections of the potassium isotopes

“…Detailed measurements of the relative γ-ray intensity depopulating the capture state in 40 K were done by von Egidy et al [3] on a natural potassium target, and by Krusche et al [4,5] who measured relative γ-ray intensities depopulating the capture states in 41,42 K using enriched targets. For each isotope nearly 100% of the total γ-ray cross section feeding the ground state was observed.…”

“…Isotopic γ-ray cross sections were determined assuming the normal potassium isotopic abundances [15]. The original von Egidy et al [3] and Krusche et al [4,5] data were normalized assuming the total observed intensity feeding the GS is 100. Weak transitions not observed in our work but seen in the earlier experiments were renormalized by a least-squares fit to the Budapest cross section data and used to complete the (n,γ) level schemes.…”

“…Weak potassium transition cross sections were calibrated by their relative intensities with respect to the 770.3-keV γ-ray. The γ-rays were assigned to level schemes for the three potassium isotopes 40 K, 41 K, and 42 K on the basis of energy and intensity by comparison with data from the ENSDF [14] file and with the potassium neutron capture data of von Egidy et al [3] and Krusche et al [4,5]. Isotopic γ-ray cross sections were determined assuming the normal potassium isotopic abundances [15].…”

“…The relatively low level density for the potassium isotopes allows the observation of a significant portion of their decay schemes [3][4][5] including the ground-state transitions from levels up to near the neutron separation energy so this correction is expected to be small. We compared the intensities of individual transitions simulated by the DICEBOX code with experiment assuming that all transitions with intensities I higher than the detection threshold I thr were observed and transitions with I < I thr were not observed.…”

“…The cross sections were internally standardized using a stoichiometric KCl target with well known 35 Cl(n,γ) γ-ray cross sections [1,2]. These data were combined with γ-ray intensities from von Egidy et al [3] and Krusche et al [4,5] to generate nearly complete capture γ-ray level schemes. Total radiative neutron cross sections were deduced from the total γ-ray cross section feeding the ground state, σ0 = Σσγ (GS) after correction for unobserved statistical γ-ray feeding from levels near the neutron capture energy.…”