Evaluation Home Page |
| Information on mass chains and nuclides |
|
 |
9He (1974AJ01)
(Not illustrated)
9He is predicted to be particle unstable: its calculated mass excess > 40.17 MeV (1970WA1G, 1972WA07), = 43.54 MeV (1972TH13). Particle instability with respect to 8He + n, 7He + 2n and 6He + 3n implies atomic mass excesses greater than 39.7, 42.25 and 41.812 MeV, respectively. See also (1968CE01). 9He has not been observed in a pion experiment [9Be(π-, π+)9He] (1965GI10) nor in the spontaneous fission of 252Cf (1967CO36).