TUNL Nuclear Data
Evaluation Home Page

Information on mass
chains and nuclides
3 4
5 6
7 8
9 10
11 12
13 14
15 16
17 18
19 20
 
Group Info
Publications
HTML
General Tables
Level Diagrams
Tables of EL's
NSR Key# Retrieval
ENSDF
Excitation Functions
Thermal N Capt.
G.S. Decays
Half-Lives Table
TUNL Dissertations
NuDat at BNL
Useful Links
Citation Examples
 
Home
Sitemap
Directory
Email Us


WWW TUNL

USNDP

8He (1979AJ01)


(See the Isobar Diagram for 8He)

GENERAL: See also (1974AJ01).

See (1973AL1B, 1973TO16, 1974IR04, 1974MA1E, 1975AB1D, 1975BE31, 1976BE1G, 1976IR1B, 1976VA29, 1978KO1H, 1978NA07).

Mass of 8He: The atomic mass excess of 8He is 31596 ± 7 keV (1977TR07). See also (1974CE05, 1975JA10, 1975KO18, 1978RO01). 8He is then stable with respect to decay into 6He + 2n by 2.141 MeV. See also (1974AJ01, 1976TR1B) and (1975JE02; theor.). The IMME coefficients based on the latest masses of the T = 2 states in A = 8 are calculated by (1977TR07).

1. 8He(β-)8Li Qm = 10.649

The half-life is 122 ± 2 msec. The decay takes place 88% to 8Li*(0.98) [log ft = 4.19 (M.J. Martin, Nucl. Data Project, private communication.)] [consistent with Jπ = 1+ for 8Li*(0.98)] and (12 ± 1)% via 8Li states which decay by neutron emission (1965PO06). See also (1973AN11, 1976DE31).

2. 18O(α, 14O)8He Qm = -37.962

At Eα = 58 MeV, θlab = 8°, the differential cross for formation of 8Heg.s. is 40 ± 15 nb/sr (1975JA10).

3. 26Mg(α, 22Mg)8He Qm = -44.989

This reaction has been studied at Eα = 80 MeV (1966CE01) and 110.6 MeV (1974CE05).