ADOPTED LEVELS for 24O

Authors: M. Shamsuzzoha Basunia, Anagha Chakraborty |  Citation: Nucl. Data Sheets 186, 2 (2022) |  Cutoff date: 31-Mar-2022 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=10.96×103 keV 19S(n)= 4.19×103 keV 20S(p)= 2.551×103 keV 45Q(α)= -21.43×103 keV 28
Reference: 2021WA16

References:
  A  25O n decay (2.7×10-9 PS)  B  26O 2n decay (4.5 PS)
  C  1H(24O,p’)  D  1H(25F,2p)
  E  2H(24O,2N22O)  F  9Be(26F,NX)
  G  9Be(26Ne,2PX) 

General Comments:

1970Ar09: 24O produced and identified in 232Th(22Ne,X) reaction at 174 MeV, measured yield. α total of ≈30 events were assigned to 24O.

1990Mu06 (also 1990Gu02): 181Ta(48Ca,x) E=2100 MeV. Mass separation, semiconductor telescope, 4π neutron detector, measured half-life and delayed neutron emission probability

1999Re16 (also 2001Pe14): Be(36S,x) E=78 MeV. GANIL, mass separation, tof. Measured half-life and delayed neutron emission probability

2003Th07 (also 2003Th10): 12C(25F,24O) E=50 MeV/nucleon. Secondary beam from 48Ca(Be,x) E=110 MeV/nucleon fragmentation. Mass separation, E-ΔE Si surface barrier detectors. Measured production cross section σ=3.8 mb 6.

2004St08, 2004St10: C(36S,X) E=77.5 MeV/nucleon. Mass separation, tof, 74 BaF2 γ-ray detectors. No gammas observed suggesting that first 2+ level is unbound to particle emission.

2009Ka14 propose doubly-closed shell nature of 24O from experimental study of neutron knockout from 24O in C(24O,23O) reaction

Other references of yield measurements in fragmentation reactions: 2012Kw02, 2007No13, 2004Th15, 2003Oz01, 2000Oz01.

Precise mass measurement: 2007Ju03. Others: 1991Or01, 1988Wo09, 1987Gi05.

DICT$ 25O n decay (2.7×10-9 ps)=25O n decay (2.7×10-9 ps

DICT$ 26O 2n decay (4.5 ps)=25O en decay (4.5 ps)

DICT$ 1H(24O,p’)=1H(24O,p’)

DICT$ 2H(24O,2N22O)=2H(24O,2n22O)

Q-value: S(2n)=6930 170, S(2p)=49690 280, Q(β-n)=7140 170 (2021Wa16)






E(level)
(keV)
XREFJπ(level) T1/2(level)
   0.0ABCD FG 0+ 72 ms 5 
% β- = 100
% β-n = 42 5
   4.76E3 21   C  F  2+ 0.05 MeV +21-5 
% n ≈ 100
   5.33E3 21   C  F  (1+) 0.03 MeV +12-3 
% n ≈ 100
  ≈7.4E3  C     (-) % n ≈ 100
   7.65E3 21     EF  (+) 0.1 MeV
% 2n ≈ 100

T1/2(level): LABEL=T1/2 or Γ

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
   0.00+ 72 ms 5 
% β- = 100
% β-n = 42 5
Measured mean matter radius=3.19 fm 13 (2001Oz03) in C(24O,X) reaction at GSI facility.
E(level): Measured mean matter radius=3.19 fm 13 (2001Oz03) in C(24O,X) reaction at GSI facility.
   4.76E32+ 0.05 MeV +21-5 
% n ≈ 100
β2=0.15 4
No γ rays observed in the work of 2004St08 (also 2004St10), suggesting that this state is unbound to particle emission.
T1/2(level): From 2009Ho01 for decay to 1/2+ g.s. in 23O from Breit-Wigner line-shape analysis of 23O-neutron coincidence spectrum.
   5.33E3(1+) 0.03 MeV +12-3 
% n ≈ 100
Possible configuration: ν1s1/2-1~#ν0d3/21.
T1/2(level): From 2009Ho01 for decay to 1/2+ g.s. in 23O from Breit-Wigner line-shape analysis of 23O-neutron coincidence spectrum.
   7.4E3(-) % n ≈ 100
E(level): The 7.4-MeV group reported in 1H(24O,p’) (2012Ts03) and 7.6-MeV group seen in 9Be(26F,nX) (2011Ho05) are considered as separate states here since the former is observed to decay by only one neutron emission to 23O, while the latter is observed to decay by two sequential neutrons to 22O. Based on assigned configurations, the 7.4-MeV group is tentatively assigned a negative parity while possible positive parity is assigned to the 7.6-MeV group. However, the possibility still remains that there is only one state near this energy, which decays by the one-, and two-neutron channels, and that the ratio of the two decay modes is yet to be determined.
   7.65E3(+) 0.1 MeV
% 2n ≈ 100
Γ from 2011Ho05 (26F,nX). Other: < 2 MeV (2015Jo14 - (24O,2n22O)).
E(level): Γ from 2011Ho05 (26F,nX). Other: < 2 MeV (2015Jo14 - (24O,2n22O)). The 7.4-MeV group reported in 1H(24O,p’) (2012Ts03) and 7.6-MeV group seen in 9Be(26F,nX) (2011Ho05) are considered as separate states here since the former is observed to decay by only one neutron emission to 23O, while the latter is observed to decay by two sequential neutrons to 22O. Based on assigned configurations, the 7.4-MeV group is tentatively assigned a negative parity while possible positive parity is assigned to the 7.6-MeV group. However, the possibility still remains that there is only one state near this energy, which decays by the one-, and two-neutron channels, and that the ratio of the two decay modes is yet to be determined.

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