ADOPTED LEVELS, GAMMAS for 194Po

Authors: Jun Chen and Balraj Singh |  Citation: Nucl. Data Sheets 177, 1 (2021) |  Cutoff date: 3-Sep-2021 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-10288 keV 27S(n)= 10751 keV 19S(p)= 2409 keV 15Q(α)= 6987 keV 3
Reference: 2021WA16

References:
  A  194Po IT decay (12.9 μs)  B  198Rn α decay (65 MS)
  C  170Yb(28Si,4nγ) 

General Comments:

Isotope produced in heavy-ion reactions and identified by mass separation: 1967Si09, 1977De32, 1981Le23, 1984YaZY, 1985Va03, 1993Wa04

Mass measurement by Schottky spectrometry: 2002No01, 1998GeZY

2011Co01 (also 2012Co24): 194Po produced in spallation reaction using UCx target and 1.4 GeV proton beam at CERN-ISOLDE facility. Resonant ionization laser spectroscopy. Measured isotope shifts and deduced rms nuclear charge radius relative to that of 210Po

Theoretical references: consult the NSR database (www.nndc.bnl.gov/nsr/) for 91 primary references dealing with nuclear structure, and half-lives in different decay modes.

Q-value: S(2n)=19081 17, S(2p)=3031 14, Q(ε)=5018 14, Q(εp)=3936 17 (2021Wa16)










E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0.0ABC 0+ 0.392 s 4 
% ε = 7 7
% α = 93 7
     
   319.31 10 ABC 2+ 26 ps 5    319.3 1 
  100
E2
     0.0
0+
   685.46 14 A C 4+ 9.7 ps 28    366.1 1 
  100
E2
   319.31
2+
   757.67 12 A C (2+)     438.4 1 
  757.7 2 
  100 14 
   71 14 
[M1+E2]
(E2)
   319.31
     0.0
2+
0+
  1147.19 24 A C 6+     461.7 2 
  100
(E2)
   685.46
4+
  1210.38 17 A C (4+)     453.9 5 
  524.9 1 
   88 22 
  100 17 
(E2)
[M1+E2]
   757.67
   685.46
(2+)
4+
  1644.39 23 A C (6+)     434.1 2 
  958.7 4 
  100 13 
   39 6 
[E2]

  1210.38
   685.46
(4+)
4+
  1692.2 3 A C 8+     545.0 1 
  100
(E2)
  1147.19
6+
  1984.7 5 A C (7-)     340.5 4 
  100
(E1)
  1644.39
(6+)
  2065.6 3 A C (8+)     373.3 1 
  421S
  918.5 2 
  100 5 
   ≤5.9
   39.0 25 
[M1+E2]


  1692.2
  1644.39
  1147.19
8+
(6+)
6+
  2281.7 6 A C (9-)     297.3 5 
  100
(E2)
  1984.7
(7-)
  2294.0 4   C 10+     601.8 3 
  100
(E2)
  1692.2
8+
  2313.6 3 A   (10-) 12.9 µs 5 
% IT = 100
   33S
  248.0 1 
  622S
 
  100 6 
  ≤12

(M2)
[M2]
  2281.7
  2065.6
  1692.2
(9-)
(8+)
8+
  2623.2 5   C 12+     329.2 3 
  100
(E2)
  2294.0
10+
  2653.8 8 ?  C (10)     371.9 5 ?
  100
(D)
  2281.7
(9-)
  2915.3 6   C (14+)     292.1 3 
  100
[E2]
  2623.2
12+
  3325.3 8 ?  C (16+)     409.9 5 ?
  100
[E2]
  2915.3
(14+)

E(level): From a least-squares fit to Eγ values

Jπ(level): As proposed by 1999He32 based on γ(θ) data and systematics of heavier Po nuclides.

M(γ): Assigned by evaluators based on γ(θ) data in (28Si,4nγ) (1999He32), and RUL (for E2 and M2 transitions) for gamma rays from levels of known half-lives, and assuming half-lives of no longer than 20 or so nanoseconds for other levels (for in-band transitions). Exceptions are noted

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Band Transitions:

E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - g.s. band
     0.0 0+ 0.392 s 4 
% ε = 7 7
% α = 93 7
     
   319.31 10  2+ 26 ps 5    319.3 1 
  100
E2
     0.0
0+
   685.46 14  4+ 9.7 ps 28    366.1 1 
  100
E2
   319.31
2+
  1147.19 24  6+     461.7 2 
  100
(E2)
   685.46
4+
  1692.2 3  8+     545.0 1 
  100
(E2)
  1147.19
6+
  2294.0 4  10+     601.8 3 
  100
(E2)
  1692.2
8+
  2623.2 5  12+     329.2 3 
  100
(E2)
  2294.0
10+
  2915.3 6  (14+)     292.1 3 
  100
[E2]
  2623.2
12+
  3325.3 8  (16+)     409.9 5 ?
  100
[E2]
  2915.3
(14+)
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - Band based on (2+)
   757.67 12  (2+)        
  1210.38 17  (4+)     453.9 5 
  524.9 1 
   88 22 
  100 17 
(E2)
[M1+E2]
   757.67
   685.46
(2+)
4+
  1644.39 23  (6+)     434.1 2 
  958.7 4 
  100 13 
   39 6 
[E2]

  1210.38
   685.46
(4+)
4+
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 3 - Sequence based on (7-)
  1984.7 5  (7-)        
  2281.7 6  (9-)     297.3 5 
  100
(E2)
  1984.7
(7-)
  2653.8 8  (10)     371.9 5 ?
  100
(D)
  2281.7
(9-)

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Additional Gamma Data:













E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityConversion
Coefficient		Additional Data
   319.31 2+ 26 ps 5    319.3 1 E20.1048B(E2)(W.u.)=89 +21-14, α=0.1048
   685.46 4+ 9.7 ps 28    366.1 1 E20.0712B(E2)(W.u.)=124 +50-28, α=0.0712
   757.67 (2+)     438.4 1 [M1+E2]0.11α=0.11 7
  1147.19 6+     461.7 2 (E2)0.0390α=0.0390
  1210.38 (4+)     453.9 5 (E2)0.0408α=0.0408
(4+)     524.9 1 [M1+E2]0.07α=0.07 5
  1644.39 (6+)     434.1 2 [E2]0.0455α=0.0455
  1692.2 8+     545.0 1 (E2)0.0262α=0.0262
  1984.7 (7-)     340.5 4 (E1)0.0235α=0.0235
  2065.6 (8+)     373.3 1 [M1+E2]0.17α=0.17 11
  2281.7 (9-)     297.3 5 (E2)0.1301α=0.1301
  2294.0 10+     601.8 3 (E2)0.0210α=0.0210
  2313.6 (10-) 12.9 µs 5 
% IT = 100
  248.0 1 (M2)3.50B(M2)(W.u.)=0.0120 +5-6, α=3.50
(10-) 12.9 µs 5 
% IT = 100
  622[M2]0.191B(M2)(W.u.)<1.6×10-5, α=0.191
  2623.2 12+     329.2 3 (E2)0.0960α=0.0960
  2653.8 (10)     371.9 5 (D)0.15α=0.15 13
  2915.3 (14+)     292.1 3 [E2]0.1365α=0.1365
  3325.3 (16+)     409.9 5 [E2]0.0528α=0.0528

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.00+ 0.392 s 4 
% ε = 7 7
% α = 93 7
<r2>1/2=5.517 fm 18 (2013An02 evaluation).
E(level): <r2>1/2=5.517 fm 18 (2013An02 evaluation). g.s. band.
   319.312+ 26 ps 5  Qt=5.5 6, β2t=0.18 2 from (28Si,4nγ) (2008Gr04).
E(level): g.s. band.
T1/2(level): From recoil-decay tagging technique in recoil-distance Doppler-shift (RDDS) measurements in 170Yb(28Si,4nγ) dataset, with analysis by differential-decay curve method (DDCM) using 114Cd(83Kr,3nγ) reaction (2006Gr16,2008Gr04) .
   685.464+ 9.7 ps 28  Qt=5.4 8, β2t=0.17 3 from (28Si,4nγ) (2008Gr04).
E(level): g.s. band.
T1/2(level): From recoil-decay tagging technique in recoil-distance Doppler-shift (RDDS) measurements in 170Yb(28Si,4nγ) dataset, with analysis by differential-decay curve method (DDCM) using 114Cd(83Kr,3nγ) reaction (2006Gr16,2008Gr04) .
   757.67(2+)   E(level): Band based on (2+).
  1147.196+   E(level): g.s. band.
  1210.38(4+)   E(level): Band based on (2+).
  1644.39(6+)   E(level): Band based on (2+).
  1692.28+   E(level): g.s. band.
  2294.010+   E(level): g.s. band.
  2313.6(10-) 12.9 µs 5 
% IT = 100
Possible configuration: πh9/2~#i3/2 (2016An10).
  2623.212+   E(level): g.s. band.
  2915.3(14+)   E(level): g.s. band.
  3325.3(16+)   E(level): g.s. band.

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Additional Gamma Comments:

E(level)E(gamma)Comments
   319.31   319.3E(γ): other: 319.7 3 from (28Si,4nγ)
   685.46   366.1E(γ): other: 366.5 3 from (28Si,4nγ)
   757.67   757.7E(γ): weighted average of 757.6 2 from 194Po IT decay and 758.1 5 from (28Si,4nγ)
I(γ): other: 116 84 from (28Si,4nγ)
  1147.19   461.7E(γ): weighted average of 461.6 2 from 194Po IT decay and 461.8 3 from (28Si,4nγ)
  1210.38   453.9E(γ): From 170Yb(28Si,4nγ) (1999He32)
I(γ): weighted average of 116 34 from 194Po IT decay and 76 22 from (28Si,4nγ)
  1644.39   958.7E(γ): other: 958.7 5 from (28Si,4nγ)
I(γ): weighted average of 38.8 63 from 194Po IT decay and 37 14 from (28Si,4nγ)
  1692.2   545.0E(γ): other: 545.2 3 from (28Si,4nγ)
  1984.7   340.5E(γ): weighted average of 340.1 3 from 194Po IT decay and 340.8 3 from (28Si,4nγ)
M(γ): ΔJ=(1), dipole from γ(θ) in (28Si,4nγ); (E1) from level scheme
  2065.6   373.3E(γ): other: 373.1 5 from (28Si,4nγ)
   918.5E(γ): other: 918.3 5 from (28Si,4nγ)
  2281.7   297.3E(γ): unweighted average of 296.8 2 in IT decay and 297.3 3 in (28Si,4nγ)
  2294.0   601.8E(γ): From 170Yb(28Si,4nγ) (1999He32)
  2313.6    33E(γ): unobserved γ-ray but 2016An10 indicate that the 33γ could populate the 2281 level as the weak 296.8 γ decay of the 2281 level was observed in the delayed γ ray spectroscopic data indicating population of the 2281 by an isomeric state
   248.0M(γ): From α(K)exp|<2.3 4. Value was considered as an upper limit as additional sources of Po K x-rays from significant E0 components as well as unobserved highly converted transitions cannot be ruled out. However, 2016An10 have strongly suggested M2 transition based on their observation of the Po K x-rays intensities in coincidence with other transitions as well as the intensity balance from γγ coincidence at the 8+ level, with intensity of the 248γ calculated for several other possible multipolarities
  2623.2   329.2E(γ): From 170Yb(28Si,4nγ) (1999He32)
  2653.8   371.9E(γ): From 170Yb(28Si,4nγ) (1999He32)
  2915.3   292.1E(γ): From 170Yb(28Si,4nγ) (1999He32)
  3325.3   409.9E(γ): From 170Yb(28Si,4nγ) (1999He32)

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