Energy levels of light nuclei. III Z = 11 to Z = 20

A Search for a MissingJπ=3/2+level in21Na

“…Nilsson orbits number 7, 9 and 4 respectively, have been identified [2, 5-91. Convincing candidates for additional members of the rotational bands based on these orbits have been suggested [8, 101. It is, however, discouraging that no candidate can be found for the 3/2+ member of the rotational band based on orbit 9 either in 21Ne or in 21Na. In 21Na the 1/2+ band head has an excitation energy of 2.409 MeV [2]. From comparison with the theoretical calculations made on levels in 23Na [3] one would expect to find the 3/2' member at about 3.1 MeV.…”

“…The strong coupling collective model [l] has enjoyed considerable success in describing the behaviour of nuclei around mass number 23 [2]. In the mirror nuclei 23Na and 23Mg all known levels up to about 5.5 MeV excitation energy can be fitted to this model [3, 41. One expects that other odd mass nuclei with 11 odd particles would show the same level structure.…”

“…Information on the gamma decay of the levels in 21Na is given in the compilation by Endt and Van der Leun [2] and recently also in other studies of levels in ZINa [7, 10, 131. There is however a need to measure more accurately the gamma ray energies of some weak intensity gamma lines with a large Ge(Li) detector instead of old measurements with NaI crystals. That would result in a firm establishment of the level scheme and accurate values on the level energies.…”