ADOPTED LEVELS, GAMMAS for 218Fr

Authors: Balraj Singh, M.S. Basunia, Murray Martin Et Al., |  Citation: Nucl. Data Sheets 160, 405 (2019) |  Cutoff date: 30-Oct-2019 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=408 keV 12S(n)= 5327 keV 8S(p)= 3888 keV 6Q(α)= 8014.0 keV 20
Reference: 2017WA10

References:
  A  222Ac α decay (4.9 S)  B  222Ac α decay (64 S)
  C  209Bi(18O,2αnγ) 

General Comments:

Isotopic assignment: 1951Me10 (from 226Pa α-decay chain, also 1949Me54, as listed in 2013Fr09). Later studies: 1964Mc21, 1968Ha14, 1972Es03

Theory references: consult NSR database (www.nndc.bnl.gov/nsr/) for 14 primary references for calculations of half-lives of radioactive decay modes, and three for nuclear structure

Levels: Shell-model calculations were carried out by the evaluators to compare the low-lying negative-parity structures up to 10- and excitation energy of 1 MeV using NuShellX@MSU code with jj67pn interaction, and 208Pb core with 5 valence protons in 1h9/2 and 2f7/2 orbitals, and 5 valance neutrons in 1i11/2 and 2g9/2 orbitals.

Q-value: S(2n)=12054 6, S(2p)=9775 6 (2017Wa10)










E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0.0AB  1- 1.1 ms +5-4 
% α = 100
     
   0+X  C (9-)        
    46 11 AB         
    86 8     (8-,9-) 21.9 ms 5 
% α ≈ 100
     
   112 28  B         
   163 28  B         
   193 28  B         
   255 28  B         
   272.9+X  C (11-)     272.9
  100

   0+X
(9-)
   295 28  B         
   450.0+X  C (10-)     177.1
  100
(M1)
   272.9+X
(11-)
   550 28  B         
   586.8+X  C (12+)     314.0
  100

   272.9+X
(11-)
   596.0+X  C (13-)     323.0
  100

   272.9+X
(11-)
   776.6+X  C (12-)     326.6
  100

   450.0+X
(10-)
   862.7+X  C (14+)     266.5
  275.9
  100
  ≈10


   596.0+X
   586.8+X
(13-)
(12+)
   940.0+X  C (13+)     163.5
  100

   776.6+X
(12-)
   973.1+X  C (15-)     110.3
  377.2
  ≈20
  100
(E1)

   862.7+X
   596.0+X
(14+)
(13-)
  1143.8+X  C (14-)     203.8
  367.1
  ≈30
  100


   940.0+X
   776.6+X
(13+)
(12-)
  1192.1+X  C (16+)     219.0
  329.4
  100
  ≈20


   973.1+X
   862.7+X
(15-)
(14+)
  1421.7+X  C (17-)     229.5
  448.7
  100
  100


  1192.1+X
   973.1+X
(16+)
(15-)
  1572.4+X  C (18+)     150.6
  380.5
  ≈45
  100
(E1)

  1421.7+X
  1192.1+X
(17-)
(16+)
E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
  1582.9+X  C (16-)     439.1
  100

  1143.8+X
(14-)
  1921.7+X  C (19-)     500.0
  100

  1421.7+X
(17-)
  2035.1+X  C (20+)     462.7
  100

  1572.4+X
(18+)
  2065.1+X  C (18-)     482.2
  100

  1582.9+X
(16-)
  2477.9+X  C (21-)     556.2?
  100

  1921.7+X
(19-)
  2527.5+X  C (22+)     492.4
  100

  2035.1+X
(20+)
  3045.1+X  C (24+)     517.5
  100

  2527.5+X
(22+)

E(level): From least-squares fit to Eγ data from (18O,2αnγ), unless otherwise noted.

Jπ(level): From probable (reflection asymmetric) band assignments for states above the ground state.

M(γ): From intensity balance in (18O,2αnγ)

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Band Transitions:

E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - s=-1 band, π=-.
   450.0+X (10-)        
   776.6+X (12-)        
  1143.8+X (14-)        
  1582.9+X (16-)        
  2065.1+X (18-)        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - s=+1 band, π=-.
   0+X (9-)        
   272.9+X (11-)        
   596.0+X (13-)        
   973.1+X (15-)        
  1421.7+X (17-)        
  1921.7+X (19-)        
  2477.9+X (21-)        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 3 - s=+1 band, π=+.
   586.8+X (12+)        
   862.7+X (14+)        
  1192.1+X (16+)        
  1572.4+X (18+)        
  2035.1+X (20+)        
  2527.5+X (22+)        
  3045.1+X (24+)        

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.01- 1.1 ms +5-4 
% α = 100
Only α decay has been observed by 1964Mc21 and 1982Ew01.
   0+X(9-)   2014Bu06 suggested that this level may be the same as the 86-keV level with Jπ=(8-) from 1999Sh03 due to similar configuration as reported by 2000De36.
E(level): s=+1 band, π=-.
    46   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
    86(8-,9-) 21.9 ms 5 
% α ≈ 100
μ=+2.68 4 (2014Bu06)
Only the α-decay mode has been observed. The isomeric decay mode may be possible if intermediate levels of appropriate spins exist between this level and the ground state.
E(level): Only the α-decay mode has been observed. The isomeric decay mode may be possible if intermediate levels of appropriate spins exist between this level and the ground state.
   112   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   163   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   193   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   255   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   272.9+X(11-)   E(level): s=+1 band, π=-.
   295   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   450.0+X(10-)   Evaluators’ shell-model calculations predict 10- levels at 463 and 492 keV.
E(level): s=-1 band, π=-.
   550   E(level): Level energies are from Eα values measured in 4.9- and 64S 222Ac decays. The relative energies of the α decaying levels in 222Ac have not been determined. The Eα=7000 20 from the 64S isomer and Eα=7008.6 20 from the 4.9-s g.s. determine the excitation energies of the connecting levels to be very similar: E(level in 218Fr fed from 64S 222Ac)- E(64S parent 222Ac level)=9 21.
   586.8+X(12+)   E(level): s=+1 band, π=+.
   596.0+X(13-)   E(level): s=+1 band, π=-.
   776.6+X(12-)   E(level): s=-1 band, π=-.
   862.7+X(14+)   E(level): s=+1 band, π=+.
   973.1+X(15-)   E(level): s=+1 band, π=-.
  1143.8+X(14-)   E(level): s=-1 band, π=-.
  1192.1+X(16+)   E(level): s=+1 band, π=+.
  1421.7+X(17-)   E(level): s=+1 band, π=-.
  1572.4+X(18+)   E(level): s=+1 band, π=+.
  1582.9+X(16-)   E(level): s=-1 band, π=-.
  1921.7+X(19-)   E(level): s=+1 band, π=-.
  2035.1+X(20+)   E(level): s=+1 band, π=+.
  2065.1+X(18-)   E(level): s=-1 band, π=-.
E(level)Jπ(level)T1/2(level)Comments
  2477.9+X(21-)   E(level): s=+1 band, π=-.
  2527.5+X(22+)   E(level): s=+1 band, π=+.
  3045.1+X(24+)   E(level): s=+1 band, π=+.

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