On21Na states betweenE x=5.5 and 6.2 MeV

Abstract

Abstract. States in 21Na between 5.5 and 6.2 MeV have been investigated by means of the Z~176 2~ p')Z~ and 2~176 reactions. The gas target is Ne in naturally occurring abundances or enriched to 99.9 % in ZONe. No new levels were seen but a new value of the spin of the 5.814 MeV state is given: J~=7/2 -. The J~=(5/2, 7/2) assignment of the 6.076 MeV level is confirmed.

Structure of the mirror nuclei21Ne and21Na

“…In Table 3 we have assigned correspondences of mirror levels in ZlNe and 21Na under the assumptions that all reported resonances [9,[31][32][33][34] in the Z~ + p reaction, including the doublet nature (J== 3/2 + and 7/2-) of the Ex = 5021 keV level [32], are valid, along with all//-delayed proton groups reported in the work of Sextro et al [263. However, within this context we reinterpret the groups @ 13 and @ 15 of [26] as transitions leading to the first excited rather than the ground state of ZONe.…”

“…The primary sources of information on the 21Na level scheme are elastic and inelastic proton scattering on 2~ [9,[31][32][33][34] and the fl-decay of alMg [26]. Hence the results of different reactions must be combined and the existing accuracy in some of the measured excitation energies makes this task difficult.…”

“…The primary sources of information on the 21Na level scheme are elastic and inelastic proton scattering on 2~ [9,[31][32][33][34] and the fl-decay of alMg [26]. 33; k Recalculated from [26], see text; ~ Ref. Levels in 2 tNa above 2.43 MeV excitation energy are unbound to proton decay and show up as reso- [9], using (1), estimated error _+30%; iS deduced using (1), estimated error _+-" J Ref.…”