ADOPTED LEVELS for 9C

Authors: J.H. Kelley, B. Grees |  Citation: ENSDF |  Cutoff date: 31-July-2020 

 Full ENSDF file | Adopted Levels (PDF version) 


S(n)= 14225 keV 18S(p)= 1299.6 keV 24Q(α)= -10650 keV SY
Reference: 2017WA10

References:
  A  1H(8B,p)  B  1H(9C,p)
  C  1H(10C,9C)  D  2H(8B,9C)
  E  6Li(3He,π-)  F  7Be(3He,n)
  G  9Be(π+-)  H  9Be(9C,9C)
  I  9Be(10C,9C)  J  9Be(13O,X):11O 2p decay
  K  10B(p,2n),11B(p,3n),12C(p,D2N)  L  10B(7Li,8He)
  M  10B(14N,15C)  N  12C(μ-,9C),14N(μ-,9C)
  O  12C(p,9C)  P  12C(3He,6He)
  Q  12C(9C,X)  R  12C(12C,9C)
  S  12C(14N,9C)  T  93Nb(20Ne,9C)

General Comments:

Previous evaluations of 9C are found in (1955Aj61, 1959Aj76, 1966La04, 1974Aj01, 1979Aj01, 1984Aj01, 1988Aj01, 2004Ti02)

Larger theoretical review articles: (2001Ka66, 2001Ar22)

Shell model analyses of the properties of light nuclei: (1970Co28, 1974Ir04, 1993Po11, 1998Na17, 1999Ki28, 2001Co21, 2014Vo09, 2015Ti03)

Cluster model analyses of light nuclei: (1995Va18, 1995Va31, 1996Ka14, 1997Ho04, 1997Ka25, 1997Va05, 2001Ka66, 2001Ar22, 2009Fu09, 2014Ko03)

Hartree Fock analyses of light nuclei: (1987Sa15, 1997Ba54, 1998Sh16, 2003Ch79, 2004Sa58, 2010Ha18, 2011Ha38)

Other theoretical approaches: (1996Re19, 1996Su24, 1997Po12, 1998Su18, 2012No09, 2013Ma60, 2019Fo17)

Studies in the 9C-9Li mirror states, and α=9 analog states. \ (1995Va18, 1995Va31, 1997Po12, 2012Br07, 2019Fo17).

Discussions on p-p pairing interactions and 9C as a proton halo nucleus: (2002Gu10, 2009Fu09, 2010Ha18, 2014Ko03)

Notable:

2014Vo09: Continuum shell model calculations of levels up to Ex≈10 MeV.

2019Fo17: Potential model analysis of mirror states in 9C and 9Li. Predictions are made for the first s and (sd)2 states in 9Li based on 9C observations.

The 9C β+, β+p and β+α decay studies are reported in: (1965Ha09, 1972Es05, 1971Ha05, 1971Mo01, 1988Mi03, 1995Ma48, 1996Ma38, 1998Hu08, 2000Ge09, 2001Be51, 2001Bu05, 2002Be53, 2002Bo29, 2004Bo22, 2004Bo43, 2005Mi30)

Compilations of decay properties for a global collection of nuclei are found in (1973Ha77, 1977Ce05, 1993Ch06).

Discussions on searches for evidence of second-class currents in β decay are found in (1970Wi02, 2003Sm02)

Other experimental studies:

1997We03: Analyzed 197Au(12C,X) isotope production at E(12C)≈47 MeV/nucleon to estimate the reaction temperature.






E(level)
(keV)
XREFJπ(level) T1/2(level)
     0.0 BCDEFG IJKLMNOPQRST 3/2- 126.5 ms 10 
% β+p = 62.0 19
% B+A = 37.9 58
% ε = 100
  2218 11 A   E  H       P     1/2- 52 keV 11 
% p ≈ 100
  3542 20 A      H       P     5/2- 673 keV 50 
% p ≈ 100
  4400 40 A      H       P     5/2+ 2.75 MeV 11 
% p ≈ 100
  5750 40        H             601 keV 50 
% p ≈ 100
     9E3    E                 
    15E3    E                 

T1/2(level): LABEL=t or Γ

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.03/2- 126.5 ms 10 
% β+p = 62.0 19
% B+A = 37.9 58
% ε = 100
μ=-1.3914 5, T=3/2
The β decay of 9C always results in p+2α either by 9C(β+p)8Be|)2α or 9C(β+α)5Li|)p+α. The decay rates here are from the respective 8Be: 9C β+p and 5Li: 9C β+α data sets in ENSDF. There are essentially two precision measurements given in (2000Ge09, 2001Be51). As in (2004Ti02) we take the 9C branch feeding the 9B g.s. to be 54.1 from (2001Be51), where extra care was taken to avoid low-energy threshold concerns; the branches feeding other levels were taken from (2000Ge09) and renormalized to give a 100% feeding (×46.9/54.1≈0.86). (2000Ge09) also found a large background branch (approx 4%), which was attributed to tails from higher states; this intensity is included but not attributed to any states.
E(level): The β decay of 9C always results in p+2α either by 9C(β+p)8Be|)2α or 9C(β+α)5Li|)p+α. The decay rates here are from the respective 8Be: 9C β+p and 5Li: 9C β+α data sets in ENSDF. There are essentially two precision measurements given in (2000Ge09, 2001Be51). As in (2004Ti02) we take the 9C branch feeding the 9B g.s. to be 54.1 from (2001Be51), where extra care was taken to avoid low-energy threshold concerns; the branches feeding other levels were taken from (2000Ge09) and renormalized to give a 100% feeding (×46.9/54.1≈0.86). (2000Ge09) also found a large background branch (approx 4%), which was attributed to tails from higher states; this intensity is included but not attributed to any states.
Jπ(level): From comparison with the mirror 9Li.
  22181/2- 52 keV 11 
% p ≈ 100
T=3/2
Jπ(level): From comparison with the mirror 9Li.
  44005/2+ 2.75 MeV 11 
% p ≈ 100
T=3/2
Decays via p+8B*(770 keV: Jπ=1+)|)2p+7Be.
  5750 601 keV 50 
% p ≈ 100
T=3/2
Decays via p+8B*(2320 keV: Jπ=3+)|)2p+7Be.
     9E3   Γ: broad.
E(level): Decay mode not specified.
    15E3   Γ: broad.
E(level): Decay mode not specified.

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