Abstract
Owing to its importance in stellar helium burning, we have carefully remeasured the excitation energy of the second excited state of with a tandem accelerator and a broad-range magnetic spectrograph. The excitation energy of this state is found to be 7655.9 ± 2.5 keV, in excellent agreement with two other recent measurements. This value lowers the calculated rate of the helium-burning process in stars by a factor of ≅3 from that previously assumed. A simultaneous measurement of the first excited state of gives 4442.2 ± 1.5 keV. A comparison is made with recent -ray measurements of this state.
- Received 14 June 1971
DOI:https://doi.org/10.1103/PhysRevC.4.1028
©1971 American Physical Society