ADOPTED LEVELS, GAMMAS for 191Po

Author: V.R. Vanin Et Al. |  Citation: Nucl. Data Sheets 108, 2393 (2007) |  Cutoff date: 1-Dec-2006 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-8933 keV 18S(n)= 8576 keV 16S(p)= 1759 keV 24Q(α)= 7493 keV 5
Reference: 2012WA38

References:
  A  195Rn α decay (6 MS)  B  195Rn α decay (5 MS)
  C  (HI,xnγ) 

General Comments:

Identification: 100Mo(94Mo,3n) excitation function and systematics of α-particle energies (1993Qu03); 96Mo(96Mo,n) (1997Ba25), 160Dy(36Ar,5n) E=196 MeV (1999An36).

Other references: 1999An10, 2001Hu21, 2001Ju09, 2001Le36, 2001Uu01.

Levels: For extensive discussions regarding the assignment of probable Jπ values, shape coexistence phenomena for the low-lying levels in 191Po, and multiparticle-multihole configurations underlying the level structures, see 2002An19 and references therein.

Levels: Tentative level scheme adopted from 2002An19.

Q-value: Note: Current evaluation has used the following Q record

Q-value: α least-squares adjustment of the α-ray energies determined in 2001Ke06 for the decay to levels in 187Pb, leads to a value of Q(α)=7495 8 keV.








E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
Final Levels
     0.0A C (3/2-) 22 ms 1 
% α = 99.0 10
   
    40 15  BC (13/2+) 93 ms 3 
% α = 96 4
   
   301  C (17/2+)     262
    40
(13/2+)
   668  C (21/2+)     367
   301
(17/2+)
  1132  C (25/2+)     464
   668
(21/2+)
  1671?  C (29/2+)     539
  1132
(25/2+)

E(level): The energies of the levels above the (13/2+) isomeric level are obtained from sums of γ-ray energies. No uncertainty estimates are available.

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Band Transitions:

E(level)
(keV)
Jπ(level) T1/2(level)E(γ)Final Levels
Band 1 - Band based on (13/2+) state.
    40 15  (13/2+) 93 ms 3 
% α = 96 4
   
   301 (17/2+)      
   668 (21/2+)     367
   301
(17/2+)
  1132 (25/2+)     464
   668
(21/2+)
  1671 (29/2+)     539
  1132
(25/2+)

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.0(3/2-) 22 ms 1 
% α = 99.0 10
This level decays by two main α branches to low-spin (3/2-) states in 187Pb. 2002An19 obtained: E(α)=7334 5 keV, Iα=77.0 25 %, HF=2.9 1, and E(α)=6966 10 keV, Iα=8.0 23 %, HF=1.6 5. Using the value r0(187Pb)=1.526 20 (average of r0(186Pb)=1.54 2 and r0(188Pb)=1.511 8, from 1998Ak04) one can deduce the values HF=4.0 4 and HF=2.3 7, respectively, for those two transitions. Another α branch connects this level to the high spin (13/2+) isomeric state in 187Pb, for which 2002An19 quote E(α)=7336 15 keV, Iα=15 2 %, HF=15 2. α similar recalculation of the hindrance factor for this α ray provides HF=21 4.
E(level): This level decays by two main α branches to low-spin (3/2-) states in 187Pb. 2002An19 obtained: E(α)=7334 5 keV, Iα=77.0 25 %, HF=2.9 1, and E(α)=6966 10 keV, Iα=8.0 23 %, HF=1.6 5. Using the value r0(187Pb)=1.526 20 (average of r0(186Pb)=1.54 2 and r0(188Pb)=1.511 8, from 1998Ak04) one can deduce the values HF=4.0 4 and HF=2.3 7, respectively, for those two transitions. Another α branch connects this level to the high spin (13/2+) isomeric state in 187Pb, for which 2002An19 quote E(α)=7336 15 keV, Iα=15 2 %, HF=15 2. α similar recalculation of the hindrance factor for this α ray provides HF=21 4.
    40(13/2+) 93 ms 3 
% α = 96 4
This level decays by two main α branches, for which 2002An19 find: E(α)=7376 5 keV, Iα=47.6 15 %, HF≈28 2 to the high-spin (13/2+) isomeric level in 187Pb, and E(α)=6888 5 keV, Iα=38 8 %, HF=0.76 17, to an excited (13/2+) level (2002An19). Using the value r0(187Pb)=1.526 20 (see discussion for g.s. level) the recalculated hindrance factors are HF=39 4 and HF=1.1 3, respectively.
E(level): This level decays by two main α branches, for which 2002An19 find: E(α)=7376 5 keV, Iα=47.6 15 %, HF≈28 2 to the high-spin (13/2+) isomeric level in 187Pb, and E(α)=6888 5 keV, Iα=38 8 %, HF=0.76 17, to an excited (13/2+) level (2002An19). Using the value r0(187Pb)=1.526 20 (see discussion for g.s. level) the recalculated hindrance factors are HF=39 4 and HF=1.1 3, respectively. Band based on (13/2+) state.
Jπ(level): Jπ sequence on the basis of assumed high-spin band structure built on a (13/2+) state.
   301(17/2+)   E(level): Band based on (13/2+) state.
Jπ(level): Jπ sequence on the basis of assumed high-spin band structure built on a (13/2+) state.
   668(21/2+)   E(level): Band based on (13/2+) state.
Jπ(level): Jπ sequence on the basis of assumed high-spin band structure built on a (13/2+) state.
  1132(25/2+)   E(level): Band based on (13/2+) state.
Jπ(level): Jπ sequence on the basis of assumed high-spin band structure built on a (13/2+) state.
  1671(29/2+)   E(level): Band based on (13/2+) state.
Jπ(level): Jπ sequence on the basis of assumed high-spin band structure built on a (13/2+) state.

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