|
![]() |
![]() |
![]()
13B (70AJ04)(See Energy Level Diagrams for 13B) GENERAL: See Table 13.1 [Table of Energy Levels] (in PDF or PS). See (TA60L, MO66). See also (AR69E).
The ratio of the half-life of 13B to that of 12B is 0.86 ± 0.02 (MA62D). Taking τ1/2(12B) = 20.41 ± 0.06 msec (see (68AJ02)), τ1/2(13B) = 17.6 ± 0.4 msec (MA62D). (CH68K) have observed delayed neutrons decaying with τ1/2 = 16 ± 1 msec. The branching ratios to various 13C states are shown in Table 13.2 (in PDF or PS) (MA62D, JO69E): they indicate Jπ = 1/2- or 3/2- for 13B(0). See also (59AJ76).
Proton groups have been observed to five states of 13B: see Table 13.3 (in PDF or PS) (MO59E, CA63D). Angular distribution measurements have been reported by (CA69B) in the range E(7Li) = 2.1 to 5.8 MeV (p0, p1+2, p3+4, p5, p7). The lifetimes of 13B*(3.53, 3.71, 4.13) are, respectively, > 0.3, < 0.38 and 0.062 ± 0.050 psec: Eγ = 3536.3 ± 4.2 and 4133.4 ± 7.8 keV (TH69A). See also (BE62M), (59AJ76) and 14C.
At Et = 11 MeV, proton groups are observed to ten states of 13B: see
Table 13.3 (in PDF or PS). Angular distributions have been analyzed for seven of the
13B levels (MI64E). The ground state is
formed by L = 0 transfer, leading to an unambiguous assignment of Jπ =
3/2-. See also (JA60B, MA62D, BA67HH, CH68K, BA69GG, JO69E).
|
![]() |