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

⁹He has been observed in the ⁹Be(¹⁴C, ¹⁴O) reaction at E(¹⁴C) = 158 MeV (1987BEYI) and in the ⁹Be(π^-, π⁺) reaction at E_π^- = 180 and 194 MeV (1987SE05): the atomic mass excesses are 41.5 ± 1.0 MeV and 40.80 ± 0.10 MeV, respectively. We adopt the latter value. ⁹He is then unstable with respect to decay into ⁸He + n by 1.13 MeV. (1987SE05) also report the population of excited states of ⁹He at 1.2, 3.8 and 7.0 MeV, while (1987BEYI) suggest an excited state at ≈ 1.8 MeV with Γ ≈ 3 MeV. Excited states are calculated at 1.64, 3.86 and 6.53 MeV, with J^π = 1/2⁺, 5/2⁺ and 3/2^- [(0 + 1)ℏω model space]. In the (0 + 2)ℏω model space the normal-parity excited states are at 6.44, 29.09 and 29.42 MeV with J^π = 3/2^-, 7/2^-, 3/2^-. In both cases the ground state is J^π = 1/2^-, as would be expected (1985PO10). See also (1984BE1C, 1988BEYJ), (1985AL1G, 1985SE1B, 1986FL1A, 1986FL1B, 1987HA1R, 1987PE1C, 1988SEZJ) and (1983ANZQ, 1984VA06, 1986AN07, 1987GI1C, 1987IK1B; theor.).