Nuclear Data Sheets for A = 28

First in-beamγ-ray study of the level structure of neutron-richS39

“…The excitation energy of the first 2 + state of 38 S is 1292 keV [55] and this suggests that a particle-core coupling description is appropriate for the 1517-keV J π = (11/2 − ) state of 39 S. in relation to the odd-A isotopes is rather sparse. The data presented in the figure were taken from Nuclear Data Sheet references [49,52,[55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72]. For the isotopes of sulfur and argon, the figure shows a good correlation between the behavior of the excitation energy of the first 2 + states of the even-A isotopes and the excitation energy differences of the first 11/2 − and first 7/2 − states of the odd-A isotopes with neutron number.…”

“…Following Doppler-shift energy correction of γ rays from projectilelike species, the full width at half maximum of γ -ray photopeaks is approximately 0.7% in energy. A relative photopeak efficiency calibration for the CLARA array was carried out using radioactive sources of 152 Eu, 133 Ba, and 56 Co. Gamma rays were detected in time coincidence with projectilelike fragments identified at the focal plane of the PRISMA spectrometer, thereby providing an unambiguous association of γ rays with each projectilelike binary fragment of a particular A and Z. The data acquisition trigger is provided by timing signals from the large area multiwire parallel plate avalanche counter at the focal plane of PRISMA.…”

Measurement of lifetimes inMg23

“…9(c). This strongly suggests that the 28 Si * recoil is produced in a fusion-evaporation reaction, such as 24 Mg + 12 C → 2α + 28 Si * or 24 Mg…”

“…Reactions between the beam and the surface contaminants contribute to the background in the γ -ray spectrum, but serendipitously also provide us with two unshifted γ -ray lines at high energy, namely, the 6877.88(8) keV line from 28 Si and its single-escape peak, which enable us to determine the energy calibration and the intrinsic detector resolution very precisely in the energy region of interest. (The γ -ray energy given here differs slightly from the γ -ray energy of 6877.0 keV given in the NDS evaluation [24]. The γ -ray energy given here was calculated from the excitation energies given in the NDS evaluation, corrected for the nuclear recoil energy.)…”

Probing the N= 14 subshell closure: g factor of the Mg26(21+McCormick1, Stuchbery2, Kibédi3 et al. 2018Physics Letters B

“…The calculated spin decompositions of the 2 + 1 states in 24 Mg and 26 Mg, listed in Table 3, show a strong single-proton influence in the 26 Mg(2 + 1 ) state. The behaviour of the leading terms indicates the behaviour of the g factors: For 24 Mg the 2 + 1 state has equal (26%) components of ν(2 + )⊗π(0 + ) and ν(0 + ) ⊗ π(2 + ), whereas in 26 Mg the ν(0 + ) ⊗ π(2 + ) [26,32,[44][45][46][47][48]. The theoretical g factors for 30 Mg and 32 Mg in a more realistic sdpf model space are also shown by the stars [43].…”