9C

β+-Decay Evaluated Data



Measurements
1965HA09: 9C; measured β+ delayed-proton decay, T1/2.
1971ESZR, 1972ES05: 9C; measured β-delayed p-spectrum, T1/2.
1971HA05: 9C; measured T1/2.
1971MO01: 9C; measured T1/2. 9C deduced mass excess.
1988MI03: 9C(β+); measured β-delayed Ep, Ip, β-delayed Eα, Iα, βαp-coin; deduced log ft. 9B levels deduced Iβ, Gamow-Teller transition strengths, comparison with other data.
1995MA48, 1996MA38: 9C(β+); measured β-NMR, polarized sources; deduced μ, spin expectation values.
1998HU08: 9C(β+); measured β-NMR. 9C deduced μ, spin expectation value.
2000GE09: 9C(β+); measured Eβ, Iβ, β-delayed particle spectra, coincidences, angular correlations. 9B levels deduced excitation and decay branching ratios.
2001BE51: 9C(β+); measured β-delayed Ep, Eα', pαα-coin, angular correlations. 9B deduced β-branching strengths, decay mechanism features.
2001BU05: 9C(β+) analyzed β-spectra, β-delayed particle spectra, coincidences. 9B deduced levels, J, π, Gamow-Teller strengths.
2002BE53, 2002BO29: 9C(β+); measured Ep, Eα following daughter nucleus decay.
2004BO22, 2004BO43: 9C(β+); measured β-delayed Eα', Ep, En, angular correlations. 9B deduced level energies, widths, decay branching ratios.
2005MI30: 9C(β+) analyzed transitions B(GT), symmetry effects.
Measured half-life for 9C(β+)9B

Recommended value (July, 2015): 126.5 ± 1.0 ms
Summary Table of Uncertainty Analysis: Table 09C preview (PDF)  
Measured values: 126.5 ± 2.0 ms (1971MO01)
126.5 ± 1.0 ms (1971HA05, 1972ES05)
127.0 ± 3.0 ms (1965HA09)

Previous Measurements

 

Decay to 9B* (MeV) Jπ Branching Ratio (%) B(GT)
(1988MI03) a (2000GE09) (2000GE09) (2001BU05)
0 3/2-   60 ± 10 54.1 ± 1.5 b     0.0295 ± 0.0008 c 0.033 d
2.34 ± 0.03 5/2- 17 ± 6 30.4 ± 5.8 e   0.053 ± 0.012 0.059  
 2.8 ± 0.2 f 1/2- 11 ± 5 5.8 ± 0.6 g 0.013 ± 0.002 0.019 h
5.3+14-0.5 i 1/2- i       0.017  
12.16 ± 0.10 j    5/2- k,l   5.9 ± 0.6 l   2.16 ± 0.22 m 1.0 n    
 14.0 ± 0.2 o   5/2- p    0.16 ± 0.02 q 0.36 ± 0.05 0.5     
14.633r 3/2-   0.010 3.1 r  
s 1/2-       0.0026
s 3/2-       1.3 t    
s 5/2-       0.3     
.
a) And D. Mikolas, private communication to Fay Ajzenberg-Selove (1988AJ01).
b) From (2001BE51).
c) B(GT) = 0.0184 ± 0.0006: see 2001BE51).
d) Ep = 164 keV peak (see (2000GE09) and high-energy tails added.
e) p0 decay branch is 0.5%.
f) Ex(9B) = 3.06 ± 0.3 MeV (2001BU05).
g) p0 decay branch is 90%. Γ = 2.5 MeV from the fit to this branch.
h) p0 decay branch is 0.5%.
i) From (2001BU05).
j) Ex(9B) = 12.19 ± 0.04 MeV (2001BE51); 12.16+0.03-0.4 MeV (2001BU05).
k) From the α-p angular ditribution for the α0 branch; Ex = 12.19 ± 0.04 MeV, Γ = 450 ± 20 keV; p0: 9.0 ± 1.0 %, p1: 25 ± 7 %, α: 60 ± 7 %, α1: 6 ± 4 %; B(GT) = 1.92 ± 0.24 (2001BE51).
l) Jπ assumed to be 3/2-; p0: 8.5 ± 1.0 %, p1: 18 ± 3 %, α: 74 ± 8 %, Γ = 0.45 MeV from the fit to the p0 branch (2001BE51).
m) B(GT) = 1.92 ± 0.24 (2001BE51).
n) 8Be*(3) decay added assuming same energy dependence as for 5Li(0) decay. Additional B(GT) strength pf B(GT) = 1.3 around 14.9 MeV.
o) Ex(9B) = 14.03 ± 0.10 MeV (2001BU05).
p) From (2001BU05).
q) Only p0 observed.
r) From (2001BE51). The summed energy for the decay is measured to be 14940 keV. α0: (4.8 ± 0.7) × 10-3%; Γα0/Γ = 0.46; B(F) + B(GT) is listed where B(F) = 3.0.
s) Background strength.
t) Higher-lying 3/2- states of considerable GT strength are predicted close to the β threshold (B.A. Brown, private communication to authors of 2001BU05).

9Li(β-)9Be Evaluated Data

A = 9 Beta-Decays Diagram

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Last modified: 21 May 2018