Levels in 44Ca excited by the β-decay of 44K
Abstract
The β-decay of 22 min 44K has been re-investigated with a Ge(Li) spectrometer of improved resolution and efficiency. A total of 58 γ-rays has been assigned to the decay of 44K. Of these 53 have been incorporated into a revised decay scheme containing 20 excited states. The 44K half-life was determined to be 22.15 ± 0.20 min.
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Cited by (10)
Nuclear Structure and Decay Data for A=44 Isobars
2023, Nuclear Data SheetsExperimental nuclear spectroscopic data are evaluated for 12 known nuclides of mass number A=44 (Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn). Detailed evaluated information are presented for each reaction and decay. Recommended values combining all available data are provided for all spectroscopic properties of each level, γ-ray, and decay radiation. No excited states have yet been identified in 44Si, 44P, 44Cr, and 44Mn. Information for excited states in 44Cl and 44V are limited. Nuclides of 44S, 44Ar and 44K have been studied via only a few reactions and decays, while 44Ca, 44Sc and 44Ti are the most investigated nuclides through various reactions and decays. Evaluators note that the half-life of the g.s. of 44S has been measured independently, with fairly good statistics, in three references, most precise being 100 ms 1 by 2004Gr20, but this value is in disagreement with the values of 125.5 ms 25 and 119 ms 6 by 2022Tr03, and 123 ms 10 by 1995So03. We adopted the unweighted average of this discrepant dataset. Another outstanding issue is that of the β+-delayed proton decay of 44Cr g.s. to 44V, where the T=2, 0+ IAS state in 44V is expected to be strongly populated by a superallowed β transition, but has not been definitely identified as discussed in detail by 2020Fu05. A detailed study of 44Cr decay is required to unravel the status of the T=2, 0+ IAS state in 44V. This work supersedes earlier ENSDF evaluations of A=44 by 2011Ch39 and 1999Ca45.
Nuclear Data Sheets for A = 44
2011, Nuclear Data SheetsThe experimental data are evaluated for known nuclides of mass number A=44 (Si,P,S,Cl,Ar,K,Ca,Sc,Ti,V, Cr,Mn). Detailed evaluated level properties and related information are presented, including adopted values of level and γ-ray energies, decay data (energies, intensities and placement of radiations), and other spectroscopic data. This work supersedes earlier full evaluations of A=44 published by 1999Ca45 and 1990En08 (also 1998En04 update).
No excited states are known in 44Si, 44P, 44Cr, 44Mn. Only one excited state is known in 44V and its Isobaric Analog State (IAS) has been observed but with the level energy not known. Information for 44S, 44Cl and 44Ar is limited and their radioactive decay schemes seem incomplete in view of large Q values and known excitations much below than allowed by Q values. The 44Ca, 44Sc and 44Ti nuclides remain as the most extensively studied from many different reactions and decays.
Nuclear data sheets for A = 44
1999, Nuclear Data SheetsNuclear spectroscopic information for the known nuclides of mass 44 (P,S,Cl,Ar,K,Ca,Sc,Ti,V,Mn,Cr) has been evaluated. The principal sources of the adopted levels presented are the evaluations of P. Endt (1999En08,1998En04,1978En02). The data sets for reactions and decays, including all available gamma-ray data, are based mostly on original literature. Recent high-spin and (6Li,d) data for 44Ti and new measurements of half-life of 44Ti are incorporated.
Energy levels of A = 21-44 nuclei (VII)
1990, Nuclear Physics, Section AThe experimentally determined properties of A = 21–44 nuclides are complied and evaluated with special emphasis on nuclear spectroscopy.
Separate tables for each of the nuclides reviewed present the available information about the following properties (in this order):
- •
- excitation energies Ex,
- •
- γ-ray branching ratios b(γ),
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- γ-ray mixing ratios σ,
- •
- lifetimes γm or widths Λ,
- •
- neutron, proton, or α-particle resonances,
- •
- partial widths,
- •
- single-nucleon transfer reactions,
- •
- beta-decay,
- •
- arguments for spin and parity (Jπ) and isospin (T) assignments.
For each nuclide a master table summarizing the “best” or adopted values for Ex, Jπ; T and τm or Λ precedes the auxiliary tables listed above.
The review of each A-chain concludes with a discussion of isospin multiplets.
Figures are presented of the level schemes of all nuclei and, for each A-chain, an overview of the relative energies of the ground states and lowest analogue states of all nuclei in the chain.
- •
Energy levels of A = 21-44 nuclei (VI)
1978, Nuclear Physics, Section AThe experimentally determined properties of the A = 21–44 nuclei are compiled and evaluated, special emphasis being given to nuclear structure.
Separate tables for each of the nuclides reviewed give all available information about the following properties in this order: - excitation energies (Ex),
- •
- γ-ray branching ratios,
- •
- γ-ray mixing ratios (δ),
- •
- lifetimes (τm) or widths (Λ),
- •
- spin and parity (Jπ) and isospin (T) assignments, and
- •
- any other data, on single-particle transfer, resonance levels, etc.
The “best” (or adopted) values for Ex, τm or Λ, Jπ and T are summarized in a master table.
The review of each A-chain concludes with - a discussion of isospin multiplets,
- •
- a few remarks about the experimental situation, and
- •
- a compilation of references to relevant theoretical papers.
- •
Energy levels of A = 21-44 nuclei (V)
1973, Nuclear Physics, Section AThe experimentally determined properties of energy levels of A = 21−44 nuclei are compiled and evaluated with emphasis on nuclear spectroscopy. For each of the nuclides reviewed, the available information on excitation energies, spins, parities, isospins, lifetimes or widths and observed decay is summarized in a master table.