The structure of 26Mg investigated with the (d, p) reaction

doi:10.1016/0375-9474(84)90203-3

Nuclear Physics A

Volume 430, Issue 1, 19 November 1984, Pages 234-248

https://doi.org/10.1016/0375-9474(84)90203-3 Get rights and content

Abstract

Angular distributions have been measured for the ²⁵Mg(d, p)²⁶Mg reaction at 13 MeV leading to excited states between E_x = 0 and 8 MeV. Experimental cross sections are compared with DWBA calculations and extended shell-model calculations in the full sd shell. Spin and parity restrictions are obtained for several levels in the region E_x = 6−;8 MeV. Spectroseopic factors for transitions to the lowest four positive-parity states of each spin are well reproduced by the shell-model calculations; however, in mixed configurations the largest component is systematically underestimated by the shell model. Only 60% of the strength for $s_{12}$ transfer is observed.

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Nuclear Data Sheets for A = 26
2016, Nuclear Data Sheets
Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for ²⁶O, ²⁶F, ²⁶Ne, ²⁶Na, ²⁶Mg, ²⁶Al, ²⁶Si, ²⁶P, and ²⁶S. This evaluation for A = 26 supersedes the earlier one by P. M. Endt (1998En04) and updates for some nuclides in ENSDF.
Highlights of this evaluation are the following:
This evaluation includes search results for ²⁶S nuclide and its proton–decay mode (2011Fo08).
An isomeric state (2.2 ms) in ²⁶F has been discovered by 2013Le03. The state is proposed at 643.4 keV 1 from γ–ray measurements. Internal-transition and beta-decay branches for the state are also determined. New excited levels in ²⁶Ne have been identified from ²⁶F β⁻ decay (2.2 ms).
For some ²⁶Si resonance states conflicting spin-parity assignments exist in the literature. These are identified by footnotes. 2015Do07 (³He,nγ) propose the first 0+ state above proton separation energy at an excitation energy of 5890 keV and suggested for additional independent measurements to confirm or refute the existence of 5946 keV 4. 2016Ch09 consider 5946 keV level as a distinct excited state in their reanalysis of the literature data with possible spin-parity assignment of 0+ or 4+
This evaluation also includes discovery of an isomeric state, at 164.1 keV 1, in ²⁶P by 2014NiZZ.
Renaissance of the Nilsson-model approach to light nuclei: The case of the A = 26 system
1998, Nuclear Physics A
The farthest reaching interpretation of a light nuclear system in terms of the Nilsson-model is obtained for A = 26. The T = 1 and T = 0 levels of either parity in ²⁶Mg and/or ²⁶Al are shown to be grouped in more than 35 rotational bands together containing some 55 levels in ²⁶Mg and 170 in ²⁶Al. The Nilsson-model configurations and deformations of bands are deduced from measured spectroscopic factors and electromagnetic transition rates. The experimental data are amended by shell-model calculations in the complete s-d basis space based on the universal s-d Hamiltonian. The rotational structure of positive-parity states is completely contained in the shell-model results. The Nilsson diagram gives a natural explanation of all bands. An important facet is the observation of particle-hole configurations with large K which arise from the complete alignment of particle and hole angular momenta along the major axis of deformation.
Energy levels of A = 21-44 nuclei (VII)
1990, Nuclear Physics, Section A
The 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 E_x,
- •
  - γ-ray branching ratios b(γ),
- •
  - γ-ray mixing ratios σ,
- •
  - lifetimes γ_m or widths Λ,
- •
  - neutron, proton, or α-particle resonances,
- •
  - partial widths,
- •
  - single-nucleon transfer reactions,
- •
  - beta-decay,
- •
  - arguments for spin and parity (J^π) and isospin (T) assignments.
For each nuclide a master table summarizing the “best” or adopted values for E_x, J^π; T and τ_m 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.
Spins, parities and isospins of 26Al levels: Shell-model aspects
1988, Nuclear Physics, Section A
Two preceding papers on the $^{25} Mg(p, γ)^{26} Al$ reaction have presented information on the energies, γ-ray branchings, lifetimes and resonance partial widths of ²⁶Al states in the E_x = 0−9.1 MeV region. These data (combined with information from other reactions) provide new J^π; T assignments to 127 levels (of which 111 assignments are unambiguous), as discussed in the present paper.
The states obtained from a shell-model calculation in the untruncated sd-shell are found to correspond one-to-one with the 30 lowest T = 1 and the 42 lowest T = 0 even-parity states; for many higher T = 0 states the correspondence could also be established.
An extensive comparison has been made of experimental and calculated γ-ray strengths. On the average E2_IS strengths are calculated correctly, whereas M1_IV strengths are high by a factor 1.85. For many levels the decay strengths are in excellent agreement, whereas the poor agreement for some pairs of neighbouring levels with the same J^π; T value could be ascribed to a poor description of the configuration mixing. In some cases the strength comparison has helped to establish the correspondence between calculated and experimental states.
A comparison has also been made between T = 1 levels of ²⁶Al and ²⁶Mg. For one (out of 44) ²⁶Al states the ²⁶Mg parent is unknown, whereas for one ²⁶Mg level the analogue in ²⁶ Al has not been identified.
Measurement of the Al 25 (d,n) Si 26 reaction and impact on the Al 25 (p,γ) Si 26 reaction rate
2023, Physical Review C
Measurement of the 25Al(d, n)26Si reaction and impact on the 25Al(p, γ)26Si reaction rate
2023, arXiv

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Nuclear Physics A

Abstract

References (13)

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Nucl. Instr. Meth.

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Nucl. Phys.

Cited by (19)

Nuclear Data Sheets for A = 26

Renaissance of the Nilsson-model approach to light nuclei: The case of the A = 26 system

Energy levels of A = 21-44 nuclei (VII)

Spins, parities and isospins of <sup>26</sup>Al levels: Shell-model aspects

Measurement of the Al 25 (d,n) Si 26 reaction and impact on the Al 25 (p,γ) Si 26 reaction rate

Measurement of the <sup>25</sup>Al(d, n)<sup>26</sup>Si reaction and impact on the <sup>25</sup>Al(p, γ)<sup>26</sup>Si reaction rate