**ADOPTED LEVELS for ^{243}Bk**

__Authors:__ C.D. Nesaraja, E.A. Mccutchan **|** __Citation:__ Nucl. Data Sheets 121, 695 (2014) **|** __Cutoff date:__ 30-Sep-2013

Full ENSDF file | Adopted Levels (PDF version)

Q(β-)=-2300 keV SY | S(n)= 7115 keV SY | S(p)= 3403 keV 4 | Q(α)= 6874 keV 4 | ||

Reference: 2012WA38 |

References: | |||

A | ^{247}Es α decay (4.55 M) |

E(level) (keV) | XREF | J^{π}(level) | T_{1/2}(level) |

0.0 | (3/2-) | 4.6 h 2 % ε ≈ 99.85 % α ≈ 0.15 | |

≈18 | A | (7/2+) | |

67 20 | A | (9/2+) | |

131 20 | A | (11/2+) | |

≈2200 | 5 ns % SF ≤ 100 |

E(level) (keV) | J^{π}(level) | T_{1/2}(level) | |||||

Band 1 - 7/2[633] band. α=5.7 FOR B=0.0. | |||||||

≈18 | (7/2+) | ||||||

67 20 | (9/2+) | ||||||

131 20 | (11/2+) |

__Additional Level Data and Comments__:

E(level) | J^{π}(level) | T_{1/2}(level) | Comments |

0.0 | (3/2-) | 4.6 h 2 % ε ≈ 99.85 % α ≈ 0.15 | Partial half-life for spontaneous-fission decay calculated by 1985Lo17 and 1978Po09: log[T_{1/2}(SF in years)]≈3.6 and ≈5.0 from plots in 1985Lo17 and 1978Po09, respectively, yield spontaneous fission branchings≈1.3×10^{-5}% and ≈5.1×10^{-7}%.E(level): Partial half-life for spontaneous-fission decay calculated by 1985Lo17 and 1978Po09: log[T _{1/2}(SF in years)]≈3.6 and ≈5.0 from plots in 1985Lo17 and 1978Po09, respectively, yield spontaneous fission branchings≈1.3×10^{-5}% and ≈5.1×10^{-7}%. |

18 | (7/2+) | E(level): 7/2[633] band. α=5.7 FOR B=0.0. J ^{π}(level): Hindrance factors for α decay from (7/2^{+}) ^{247}Es and the level spacings imply that these levels are probably members of a rotational band. From the unhindered character of the α transition (HF≈2.4) to the ≈18 keV level, the bandhead member should be the same state as that of the parent. Systematics of Nilsson states (see, for example, 1972El21) suggest either the 3/2[521] or the 7/2[633] orbital for ^{247}Es g.s. If the α decay was to the 3/2[521] orbital, the band parameter would be 9.4 which would not fit the local trend. By assuming a rotational band built on the 7/2[633] state, the rotational band parameter of 5.7 is consistent with band parameters for 7/2[633] bands in the region. | |

67 | (9/2+) | E(level): 7/2[633] band. α=5.7 FOR B=0.0. J ^{π}(level): Hindrance factors for α decay from (7/2^{+}) ^{247}Es and the level spacings imply that these levels are probably members of a rotational band. From the unhindered character of the α transition (HF≈2.4) to the ≈18 keV level, the bandhead member should be the same state as that of the parent. Systematics of Nilsson states (see, for example, 1972El21) suggest either the 3/2[521] or the 7/2[633] orbital for ^{247}Es g.s. If the α decay was to the 3/2[521] orbital, the band parameter would be 9.4 which would not fit the local trend. By assuming a rotational band built on the 7/2[633] state, the rotational band parameter of 5.7 is consistent with band parameters for 7/2[633] bands in the region. | |

131 | (11/2+) | E(level): 7/2[633] band. α=5.7 FOR B=0.0. J ^{π}(level): Hindrance factors for α decay from (7/2^{+}) ^{247}Es and the level spacings imply that these levels are probably members of a rotational band. From the unhindered character of the α transition (HF≈2.4) to the ≈18 keV level, the bandhead member should be the same state as that of the parent. Systematics of Nilsson states (see, for example, 1972El21) suggest either the 3/2[521] or the 7/2[633] orbital for ^{247}Es g.s. If the α decay was to the 3/2[521] orbital, the band parameter would be 9.4 which would not fit the local trend. By assuming a rotational band built on the 7/2[633] state, the rotational band parameter of 5.7 is consistent with band parameters for 7/2[633] bands in the region. | |

2200 | 5 ns % SF ≤ 100 | Assignment: ^{241}Am(α,2n) systematics (1972Ga42).E(level): Assignment: ^{241}Am(α,2n) systematics (1972Ga42). |

S(2n)=13485 syst

200; S(2p)=88234(2012Wa38)First identification: 1950Th52 in α particle bombardment of Americium, chemical separation.

Theoretical calculations:

2013Zd01: T

_{1/2}for α decay calculated with a phenomenological model based on Gamow theory with WKB approximation for Coulomb barrier penetration.2012Ni16: α decay T

_{1/2}and fine structure calculated with Multichannel cluster model2012Po01: calculated α decay T

_{1/2}with a universal decay law using α-like R matrix theory.2012Sa05,2011Sa40: calculated T

_{1/2}and α decay fine structure using Coulomb and proximity potential model.2012Zh01: β

_{2}, β_{4}, moment of inertia, and alignments calculated with a particle conserving method based on the cranked shell model.2011Zh36: partial α decay T

_{1/2}to members of favored band calculated with a microscopic quantum tunneling theory.2010Ni02: T

_{1/2}and branching ratios calculated using generalized density dependent cluster model.2008Do12: calculated binding energies with additional terms beyond standard Bethe Weizsacker formula

2004Pa40: deformation parameters, pairing gap, and single particle energy levels calculated with a macroscopic-microscopic model.

2002Lo05: calculated binding energies, Q(α), pairing gap, ground state deformation and single-particle levels with a relativistic mean field approach.

1985Lo17,1978Po09: calculated spontaneous-fission half-life of ground state.

1984Ku05: systematic study of fission-barrier parameters

1980Ka41: hindrance factors for α’s from

^{243}Bk were calculated with R-matrix method.Q-value: ΔQ(β

^{-})=114; ΔS(n)=200 (2012Wa38)