ADOPTED LEVELS, GAMMAS for 221Th

Authors: Ashok Jain, Sukhjeet Singh, Suresh Kumar, Jagdish Tuli |  Citation: Nucl. Data Sheets 108, 883 (2007) |  Cutoff date: 15-Jan-2007 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-3.44×103 keV 6S(n)= 5802 keV 24S(p)= 4095 keV 11Q(α)= 8626 keV 4
Reference: 2012WA38

References:
  A  225U α decay  B  208Pb(16O,3nγ) E=78-89 MeV

General Comments:

Assignment: parent of 217Ra, 213Rn (1970To07 and 1970Va13); 208Pb(16O,3n) excit (1970To07 and 1970Va13); cross bombardments (1970Va13).

See 1989De11 for calculations of B(E1)/B(E2) values.

Levels: See 1988Le13 for theoretical interpretation of levels, and level energy calculations by coupling states of a deformed shell model to a reflection-asymmetric rotor core. The single-particle states were obtained from a Woods-Saxon potential, including octupole deformation (octupole deformation of 0.1) as well as quadrupole deformation.

Levels: See 1991Cw01 also for deformation,level energy calculations based on the fit to the suggested parity doublet ground band. α review of the reflection asymmetric shapes may be found in 1996Bu45.

Levels: Higher-order deformations up to β7 were included by 1989Cw03 in calculations of non-collective quasiparticle state energies for odd-A thorium isotopes in the transitional region. These higher-order equilibrium deformations lead to further fragmentation of single-particle orbitals. For K=1/2 bandhead (at g.s.), β2=0.101, β3=0.090, β4=0.065, β5=0.042, β6=0.020 and β7=0.027 were obtained. See 1989Cw03 for calculated deformations and energies for the K=3/2 and 5/2 bandheads.

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










E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
     0.0AB (7/2+) 1.74 ms 3 
% α = 100
     
    47 20 ?A         
   250.9 3 AB (11/2+)     250.9 3 
  100.0
E2
     0.0
(7/2+)
   488.0 5  B (13/2-)     237.1 3 
  100.0
E1
   250.9
(11/2+)
   572.8 5  B (15/2+)      84.8 3 
  321.9 3 
   58 7 
  100 5 
E1
E2
   488.0
   250.9
(13/2-)
(11/2+)
   746.9 6  B (17/2-)     174.1 3 
  258.9 3 ?
  100 4 
    7.3 11 
E1
[E2]
   572.8
   488.0
(15/2+)
(13/2-)
   946.5 6  B (19/2+)     199.6 3 
  373.6 5 
  100 6 
   27 9 
E1
E2
   746.9
   572.8
(17/2-)
(15/2+)
  1078.6 7  B (21/2-)     132.1 3 
  332.1 3 
  100 3 
   36 6 
E1
[E2]
   946.5
   746.9
(19/2+)
(17/2-)
  1356.0 8  B (23/2+)     277.4 3 
  409.5 3 ?
  100 6 
    9 4 
E1
[E2]
  1078.6
   946.5
(21/2-)
(19/2+)
  1472.0 9  B (25/2-)     116.0 3 
  393.3 3 
  100 7 
   87 7 
E1
E2
  1356.0
  1078.6
(23/2+)
(21/2-)
  1776.4 9  B (27/2+)     304.4 3 
  420.3 10 ?
  100 9 
  <13.64
E1
[E2]
  1472.0
  1356.0
(25/2-)
(23/2+)
  1935.4 10  B (29/2-)     159.0 3 
  463.5 5 
   93 15 
  100 15 
E1
E2
  1776.4
  1472.0
(27/2+)
(25/2-)
  2251.5 11  B (31/2+)     316.1 3 
  475.0 11 ?
  100 17 
  <16.67
E1
[E2]
  1935.4
  1776.4
(29/2-)
(27/2+)
  2421.5 11  B (33/2-)     170.4 3 
  485.7 3 
   26 4 
  100 12 
[E1]
[E2]
  2251.5
  1935.4
(31/2+)
(29/2-)

E(level): 1988Da15 suggested that the 250.9-keV transition, the strongest γ seen in 208Pb(16O,3nγ) reaction, depopulates either a 250.9-keV or possibly a 250.9+x keV level; x was estimated to be less than 50 keV from the experimental limit for observations of low-energy transitions. Therefore, as pointed out by 1988Da15, all excited-state energies might be higher by an amount of E|<50 keV.

Jπ(level): Spins and parities of all excited states were deduced by 1988Da15 from multipolarities of deexciting γ transitions observed in 208Pb(16O,3nγ). If the 250.9γ feeds a low-lying level at E|<50 keV with a spin and parity different from 7/2+, then Jπ’s given here for all excited states would have to be changed by [Jπ(level populated by 250.9γ)-7/2+].

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Band Transitions:

E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - K=1/2 GS band (1988Le13).
     0.0 (7/2+) 1.74 ms 3 
% α = 100
     
   250.9 3  (11/2+)        
   572.8 5  (15/2+)      84.8 3 
  321.9 3 
   58 7 
  100 5 
E1
E2
   488.0
   250.9
(13/2-)
(11/2+)
   946.5 6  (19/2+)     199.6 3 
  373.6 5 
  100 6 
   27 9 
E1
E2
   746.9
   572.8
(17/2-)
(15/2+)
  1356.0 8  (23/2+)     277.4 3 
  409.5 3 ?
  100 6 
    9 4 
E1
[E2]
  1078.6
   946.5
(21/2-)
(19/2+)
  1776.4 9  (27/2+)     304.4 3 
  420.3 10 ?
  100 9 
  <13.64
E1
[E2]
  1472.0
  1356.0
(25/2-)
(23/2+)
  2251.5 11  (31/2+)     316.1 3 
  475.0 11 ?
  100 17 
  <16.67
E1
[E2]
  1935.4
  1776.4
(29/2-)
(27/2+)
E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - K=1/2 parity doublet of GS band (1988Le13).
   488.0 5  (13/2-)        
   746.9 6  (17/2-)        
  1078.6 7  (21/2-)     132.1 3 
  332.1 3 
  100 3 
   36 6 
E1
[E2]
   946.5
   746.9
(19/2+)
(17/2-)
  1472.0 9  (25/2-)     116.0 3 
  393.3 3 
  100 7 
   87 7 
E1
E2
  1356.0
  1078.6
(23/2+)
(21/2-)
  1935.4 10  (29/2-)     159.0 3 
  463.5 5 
   93 15 
  100 15 
E1
E2
  1776.4
  1472.0
(27/2+)
(25/2-)
  2421.5 11  (33/2-)     170.4 3 
  485.7 3 
   26 4 
  100 12 
[E1]
[E2]
  2251.5
  1935.4
(31/2+)
(29/2-)

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Additional Gamma Data:













E(level)
(keV)
Jπ(level)T1/2(level)E(γ)
(keV)
MultipolarityConversion
Coefficient
Additional Data
   250.9 (11/2+)     250.9 3 E20.304α=0.304
   488.0 (13/2-)     237.1 3 E10.0640α=0.0640
   572.8 (15/2+)      84.8 3 E10.184α=0.184
(15/2+)     321.9 3 E20.139α=0.139
   746.9 (17/2-)     174.1 3 E10.132α=0.132
(17/2-)     258.9 3 [E2]0.274α=0.274
   946.5 (19/2+)     199.6 3 E10.0957α=0.0957
(19/2+)     373.6 5 E20.0911α=0.0911
  1078.6 (21/2-)     132.1 3 E10.257α=0.257
(21/2-)     332.1 3 [E2]0.127α=0.127
  1356.0 (23/2+)     277.4 3 E10.0447α=0.0447
(23/2+)     409.5 3 [E2]0.0713α=0.0713
  1472.0 (25/2-)     116.0 3 E10.352α=0.352
(25/2-)     393.3 3 E20.0793α=0.0793
  1776.4 (27/2+)     304.4 3 E10.0363α=0.0363
(27/2+)     420.3 10 [E2]0.0666α=0.0666
  1935.4 (29/2-)     159.0 3 E10.165α=0.165
(29/2-)     463.5 5 E20.0521α=0.0521
  2251.5 (31/2+)     316.1 3 E10.0334α=0.0334
(31/2+)     475.0 11 [E2]0.0491α=0.0491
  2421.5 (33/2-)     170.4 3 [E1]0.1396α=0.1396
(33/2-)     485.7 3 [E2]0.0465α=0.0465

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.0(7/2+) 1.74 ms 3 
% α = 100
See 1985Po14 for calculated half-lives for decays by multiple heavy-ion emission; see 1973Ta30 for calculated T1/2(ε decay).
E(level): See 1985Po14 for calculated half-lives for decays by multiple heavy-ion emission; see 1973Ta30 for calculated T1/2(ε decay). K=1/2 GS band (1988Le13).
   250.9(11/2+)   E(level): K=1/2 GS band (1988Le13).
   488.0(13/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).
   572.8(15/2+)   E(level): K=1/2 GS band (1988Le13).
   746.9(17/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).
   946.5(19/2+)   E(level): K=1/2 GS band (1988Le13).
  1078.6(21/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).
  1356.0(23/2+)   E(level): K=1/2 GS band (1988Le13).
  1472.0(25/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).
  1776.4(27/2+)   E(level): K=1/2 GS band (1988Le13).
  1935.4(29/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).
  2251.5(31/2+)   E(level): K=1/2 GS band (1988Le13).
  2421.5(33/2-)   E(level): K=1/2 parity doublet of GS band (1988Le13).

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