8He

β--Decay Evaluated Data



Measurements
1963NE07: 8He; measured not abstracted; deduced nuclear properties.
1965PO06: 8He; measured not abstracted; deduced nuclear properties.
1966NE07: 8He; measured T1/2, Eγ, βγ-coin.
1973AN11: 8He; measured decay probability.
1981BJ03: 8He; measured β-delayed En, In, βγ-coin, T1/2; deduced delayed neutron branching, log ft.
1986BO41: 8He(β-); measured β-delayed triton branching ratios, spectra; deduced log ft. 8Li deduced level.
1991BO31: 8He; measured continuum particle spectra following β-decay; deduced log ft, Gamow-Teller transition strength, level width, di-neutron, neutron halo roles.
1991LUZZ: 8He; measured T1/2.
1993BO24: 8He(β-); measured β-delayed deuteron spectrum; deduced branching ratio. 8Li deduced level.
1994JO04: 8He(β-); compiled, reviewed β-decay data; deduced halo role.
1995REZZ: 8He; measured T1/2, neutron emission probabilities.
1996BA66: 8He(β-); analyzed β-decay delayed triton spectra. 8Li levels deduced parameters, B(GT), branching ratios, log ft.
1997SO34: 8He(β-n); measured decay products, En, In; deduced neutron emission probabilities.
2003BE05: 8He; measured Eβ, β-delayed neutron spectra, neutron emission probability, T1/2.
2005MI30: 8He(β-); analyzed transitions B(GT).
2010MI01: 8He(β-); measured recoils, β-delayed decays, Eα, Iα, It, Et, In, En; deduced feasibilityof β-decay studies of 8He.
2010LE19: 8He(β-); measured Eγ.

Measured half-life for 8He(β-)8Li

Recommended value (September, 2015): 119.0 ± 1.6 ms (Weighted Average)
Summary Table of Uncertainty Analysis:      Table 08He preview (PDF)  
Measured values:   116 ± 43 ms (From the unpublished private communications of (2008REZZ)/(1995REZZ))
103 ± 7 ms (2003BE05)
124.5 ± 0.2 ms (1997SO34) (Excluded: insufficient experimental details)
124.6 ± 5.0 ms (1991LUZZ)
117.5 ± 1.5 ms (1981BJ03)
120 ms (1973AN11) (Excluded)
  114 ± 25 ms (1966NE07)
122 ± 2 ms (1965PO06)
    30 ± 20 ms (1963NE07) (Excluded)
Other Reviews: 119.4 ± 1.5 ms (2015BI05)

Previous Measurements

 

Decay to
8Li* (MeV)
Jπ Branching Ratio (%) Log ft
(1965PO06) (1981BJ03) (1986BO41) a b (1981BJ03) (1986BO41) (1988BA67, 1996BA66)
0.98 1+ 88% (84 ± 1)%   4.20 4.19 4.20   4.20
3.21    1+ d (12 ± 1)% (16 ± 1)%         5.0 4.52
5.4      1+ e           4.53
≈ 9.67 c  1+   (0.9 ± 0.1)%       4.3 2.91
a) B. Zimmerman, private communication to Fay Ajzenberg-Selove (1974AJ01).
b) M.J. Martin, Nucl. Data Project, private communication to Fay Ajzenberg-Selove (1984AJ01).
c) (1986BO41) assume level at 8.8 MeV with Jπ = 1+.
d) (1981BJ03) suggest π = +.
e) (1981BJ03) suggest Jπ = 0+ or 1 +.

8Li(β-)8Be Evaluated Data

8B(β+)8Be Evaluated Data

A = 8 Beta-Decays Diagram

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Last modified: 21 May 2018