ADOPTED LEVELS, GAMMAS for 216Ra

Author: C. Morse |  Citation: Nucl. Data Sheets 209, 409 (2026) |  Cutoff date: 5-Aug-2025 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-4858 keV 12S(n)= 7312 keV 11S(p)= 4316 keV 11Q(α)= 9526 keV 7
Reference: 2021Wa16

References:
  A  220Th α decay  B  (HI,xnγ)








E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0.0AB 0+ 172 ns 7 
% α = 100
     
   688.20 20  B 2+      688.2 2 
  100
E2
     0.0
0+
  1164.1 3  B 4+ % α = 0.23
   475.9 2 
 
E2
   688.20
2+
  1507.6 3  B 6+ 0.3 ns 1 
% α = 0.58
   343.5 1 
 
E2
  1164.1
4+
  1711.1 4  B 8+ 1.27 ns 14 
% α = 1.86
   203.5 1 
 
E2
  1507.6
6+
  2026.0 4  B 10+ 0.32 ns 10 
% α = 0.12
   314.9 1 
 
E2
  1711.1
8+
  2134.6 8  B      423 1 
 

  1711.1
8+
  2335.2 4  B 11-      200 1 
   309.2 1 
   <5
  100 1 

E1
  2134.6
  2026.0

10+
  2563.2 11  B      228 1 
 

  2335.2
11-
  2679.4 4  B 13- 0.85 ns 14     344.2 1 
 
E2
  2335.2
11-
  2753.2 11  B      418 1 
 

  2335.2
11-
  2770.0 11  B      744 1 
 

  2026.0
10+
  3014.4 11  B      335 1 
 

  2679.4
13-
  3114.0 11  B     1088 1 
 

  2026.0
10+
  3292.7 5  B 14+      613.3 2 
 
E1
  2679.4
13-
  3429.9 9  B      137 1 
 

  3292.7
14+
  3513.2 5  B (16+)      220.4 2 
 
(E2)
  3292.7
14+
  3540.7 11  B      248 1 
 

  3292.7
14+
  3574.7 11  B      282 1 
 

  3292.7
14+
  3582.1 5  B (16+)      152 1 
   289.5 2 
  <33
  100 5 

(E2)
  3429.9
  3292.7

14+
  3615.7 11  B      323 1 
 

  3292.7
14+
  3642.4 15  B      628 1 
 

  3014.4

  3681.4 11  B     1002 1 
 

  2679.4
13-
  3712.1 5  B (18+)      130.4 5 
   198.9 1 
   33 9 
  100 9 
(E2)
(E2)
  3582.1
  3513.2
(16+)
(16+)
E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
  3725.7 11  B      433 1 
 

  3292.7
14+
  3763.5 5  B (19-) 5.28 ns 14      51.4 1 
 
E1
  3712.1
(18+)
  3874.3 6  B (20-)      110.8 2 
 
M1+(E2)
  3763.5
(19-)
  3994.4 6  B (21-)      120.1 2 
 
M1+(E2)
  3874.3
(20-)
  4151.6 10  B      157 1 
 

  3994.4
(21-)
  4347.8 9  B      584 1 
 

  3763.5
(19-)
  4551.2 7  B (22-)      203 1 
   556.9 3 
 
  100 3 

M1+E2
  4347.8
  3994.4

(21-)
  4646.1 11  B      934 1 
 

  3712.1
(18+)
  4697.9 10  B (23-)      147 1 
   546 1 
  100 18 
  <75
(M1+E2)

  4551.2
  4151.6
(22-)

  5096.5 11  B (24-)      398.6 2 
 
M1+E2
  4697.9
(23-)
  5354.5 11  B (26-)      258.0 2 
 
(E2)
  5096.5
(24-)
  5370.5 15  B      274 1 
 

  5096.5
(24-)
  5400.5 15  B      304 1 
 

  5096.5
(24-)
  5548.0 11  B (27-) 6.6 ns 3     193.5 2 
 
(M1+E2)
  5354.5
(26-)
  5678.4 13  B      130 1 
 

  5548.0
(27-)
  5848.8 11  B (28-)      170 1 
   300.8 3 
  <32
  100 4 

(M1+E2)
  5678.4
  5548.0

(27-)
  6210.0 12  B (30-)      361.2 2 
 
(E2)
  5848.8
(28-)
  6643.6 13  B (31-)      433.6 5 
 
(M1+E2)
  6210.0
(30-)
  6972.8 14  B (32)      329 1 
   763 1 
 
 


  6643.6
  6210.0
(31-)
(30-)
  7189.8 17  B      217 1 
 

  6972.8
(32)

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

M(γ): Multipolarity assignments are based upon DCO ratios and angular-distribution coefficients given in (HI,xnγ) dataset.

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Additional Gamma Data:













E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityConversion
Coefficient		Additional Data
   688.20 2+      688.2 2 E20.01899α=0.01899 27, α(K)=0.01374 19, α(L)=0.00394 6, α(M)=0.000986 14, α(N)=0.000260 4, α(O)=5.78×10-5 8, α(P)=9.46E-6 13, α(Q)=4.84E-7 7
  1164.1 4+ % α = 0.23
   475.9 2 E20.0435α=0.0435 6, α(K)=0.0278 4, α(L)=0.01173 17, α(M)=0.00302 4, α(N)=0.000798 11, α(O)=0.0001751 25, α(P)=2.77×10-5 4, α(Q)=1.025E-6 14
  1507.6 6+ 0.3 ns 1 
% α = 0.58
   343.5 1 E20.1023B(E2)(W.u.)=4.6 +23-12, α=0.1023 14, α(K)=0.0536 8, α(L)=0.0361 5, α(M)=0.00951 13, α(N)=0.002513 35, α(O)=0.000545 8, α(P)=8.39E-5 12, α(Q)=2.075E-6 29
  1711.1 8+ 1.27 ns 14 
% α = 1.86
   203.5 1 E20.550B(E2)(W.u.)=10.5 +13-11, α=0.550 8, α(K)=0.1564 22, α(L)=0.289 4, α(M)=0.0780 11, α(N)=0.02062 29, α(O)=0.00442 6, α(P)=0.000656 9, α(Q)=7.13E-6 10
  2026.0 10+ 0.32 ns 10 
% α = 0.12
   314.9 1 E20.1316B(E2)(W.u.)=4.8 +26-13, α=0.1316 18, α(K)=0.0641 9, α(L)=0.0499 7, α(M)=0.01322 19, α(N)=0.00349 5, α(O)=0.000756 11, α(P)=0.0001154 16, α(Q)=2.523E-6 35
  2335.2 11-      309.2 1 E10.0329α=0.0329 5, α(K)=0.0265 4, α(L)=0.00482 7, α(M)=0.001149 16, α(N)=0.000301 4, α(O)=6.73×10-5 9, α(P)=1.123E-5 16, α(Q)=7.32E-7 10
  2679.4 13- 0.85 ns 14     344.2 1 E20.1017B(E2)(W.u.)=1.63 +33-23, α=0.1017 14, α(K)=0.0533 7, α(L)=0.0358 5, α(M)=0.00944 13, α(N)=0.002494 35, α(O)=0.000541 8, α(P)=8.33E-5 12, α(Q)=2.066E-6 29
  3292.7 14+      613.3 2 E10.00787α=0.00787 11, α(K)=0.00645 9, α(L)=0.001085 15, α(M)=0.000256 4, α(N)=6.71×10-5 9, α(O)=1.517E-5 21, α(P)=2.59E-6 4, α(Q)=1.879E-7 26
  3513.2 (16+)      220.4 2 (E2)0.415α=0.415 6, α(K)=0.1336 19, α(L)=0.2069 30, α(M)=0.0557 8, α(N)=0.01471 21, α(O)=0.00316 5, α(P)=0.000470 7, α(Q)=5.85×10-6 8
  3582.1 (16+)      289.5 2 (E2)0.1696α=0.1696 24, α(K)=0.0763 11, α(L)=0.0689 10, α(M)=0.01832 26, α(N)=0.00484 7, α(O)=0.001045 15, α(P)=0.0001587 23, α(Q)=3.06×10-6 4
  3712.1 (18+)      130.4 5 (E2)3.10α=3.10 7, α(K)=0.302 4, α(L)=2.06 5, α(M)=0.559 13, α(N)=0.1478 33, α(O)=0.0315 7, α(P)=0.00459 10, α(Q)=2.38×10-5 4
(18+)      198.9 1 (E2)0.597α=0.597 8, α(K)=0.1634 23, α(L)=0.319 5, α(M)=0.0861 12, α(N)=0.02274 32, α(O)=0.00487 7, α(P)=0.000722 10, α(Q)=7.56×10-6 11
  3763.5 (19-) 5.28 ns 14      51.4 1 E10.650B(E1)(W.u.)=1.588E-4 +43-41, α=0.650 10, α(L)=0.492 7, α(M)=0.1202 18, α(N)=0.0310 5, α(O)=0.00657 10, α(P)=0.000956 14, α(Q)=3.81E-5 6
  3874.3 (20-)      110.8 2 M1+(E2)8.9α=8.9 27, α(K)=5 5, α(L)=3.0 13, α(M)=0.8 4, α(N)=0.21 10, α(O)=0.046 21, α(P)=0.0070 26, α(Q)=1.9×10-4 15
  3994.4 (21-)      120.1 2 M1+(E2)6.8α=6.8 24, α(K)=4 4, α(L)=2.2 8, α(M)=0.57 24, α(N)=0.15 6, α(O)=0.033 13, α(P)=0.0051 16, α(Q)=1.5×10-4 12
  4551.2 (22-)      556.9 3 M1+E20.08α=0.08 5, α(K)=0.06 4, α(L)=0.013 6, α(M)=0.0032 14, α(N)=9.E-4 4, α(O)=1.9E-4 9, α(P)=3.3E-5 16, α(Q)=2.3E-6 15
  4697.9 (23-)      147 1 (M1+E2)3.6α=3.6 17, α(K)=2.2 20, α(L)=0.99 21, α(M)=0.26 7, α(N)=0.068 19, α(O)=0.015 4, α(P)=0.0023 4, α(Q)=8.E-5 7
  5096.5 (24-)      398.6 2 M1+E20.20α=0.20 13, α(K)=0.15 11, α(L)=0.035 13, α(M)=0.0085 30, α(N)=0.0022 8, α(O)=5.0×10-4 18, α(P)=8.5E-5 35, α(Q)=5.E-6 4
  5354.5 (26-)      258.0 2 (E2)0.2441α=0.2441 35, α(K)=0.0969 14, α(L)=0.1086 16, α(M)=0.0290 4, α(N)=0.00767 11, α(O)=0.001652 24, α(P)=0.000249 4, α(Q)=4.00×10-6 6
  5548.0 (27-) 6.6 ns 3     193.5 2 (M1+E2)1.5α=1.5 9, α(K)=1.1 9, α(L)=0.358 5, α(M)=0.091 6, α(N)=0.0240 16, α(O)=0.00531 19, α(P)=0.00085 4, α(Q)=3.9×10-5 31
  5848.8 (28-)      300.8 3 (M1+E2)0.43α=0.43 28, α(K)=0.32 25, α(L)=0.082 22, α(M)=0.020 5, α(N)=0.0054 12, α(O)=0.00120 30, α(P)=2.0×10-4 6, α(Q)=1.2E-5 9
  6210.0 (30-)      361.2 2 (E2)0.0889α=0.0889 13, α(K)=0.0483 7, α(L)=0.0301 4, α(M)=0.00790 11, α(N)=0.002087 30, α(O)=0.000453 6, α(P)=7.01×10-5 10, α(Q)=1.856E-6 26
  6643.6 (31-)      433.6 5 (M1+E2)0.16α=0.16 10, α(K)=0.12 9, α(L)=0.027 11, α(M)=0.0066 25, α(N)=0.0017 7, α(O)=3.9×10-4 15, α(P)=6.6E-5 29, α(Q)=4.4E-6 31

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
  5548.0(27-) 6.6 ns 3  2020StZV gives μ=+15.8 μN 15 for this state (but with J=(25-) and E=5170 keV), based on Time Dependent Perturbed Angular Distribution method reported in 1985Ad09.
E(level): 2020StZV gives μ=+15.8 μN 15 for this state (but with J=(25-) and E=5170 keV), based on Time Dependent Perturbed Angular Distribution method reported in 1985Ad09.

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Additional Gamma Comments:

E(level)E(gamma)Comments
   688.20   688.2M(γ): Angular distribution indicates quadrupole transition; polarization indicates electric character.
  1164.1   475.9M(γ): The angular distribution indicates a stretched quadrupole transition, while the polarization indicates an electric character.
  1507.6   343.5M(γ): Angular distribution indicates quadrupole transition; polarization indicates electric character.
  1711.1   203.5M(γ): Angular distribution indicates quadrupole transition, polarization indicates electric character.
  2026.0   314.9M(γ): Angular distribution indicates quadrupole transition, while polarization indicates electric character.
  2335.2   309.2M(γ): The angular distribution indicates a dipole transition, while the polarization indicates electric character.
  2679.4   344.2M(γ): Angular distribution indicates quadrupole transition; polarization indicates electric transition.
  3292.7   613.3M(γ): Angular distribution indicates dipole transition; polarization indicates electric character.
  3513.2   220.4M(γ): Angular distribution and DCO ratio indicate quadrupole transition. Per discussion in 1983It01, a lifetime of about 100 ns would be expected for an M2 transition, while the observed decay lifetime is less than 8.7 ns.
  3582.1   289.5M(γ): 1983It01 notes that the angular distribution of this γ-ray is consistent with a stretched quadrupole transition, and that the Weisskopf estimate for an M2 transition would yield a 100 ns lifetime, which is not observed. Note that the intermediate DCO ratio might suggest a mixed M1+E2 transition, but this presents difficulties with the level scheme. Therefore, E2 is tentatively assigned to this transition.
  3712.1   130.4M(γ): The DCO ratio indicates a quadrupole transition, while the non-observation of a significant lifetime for this decay suggests it is not M2.
   198.9M(γ): The angular distribution is consistent with a stretched quadrupole transition (1983It01); an M2 transition would be expected to have a 100 ns lifetime, thus E2 is suggested.
  3763.5    51.4M(γ): As discussed in 1983It01, this transition must have E1 character, otherwise its total intensity (γ+ce) would be greater than that of the 2+ to 0+ transition.
  3874.3   110.8M(γ): The angular distribution and DCO ratio suggest a dipole transition. Its placement in the level scheme and the feeding intensity of the 120.1-keV transition precludes an E1 assignment.
  3994.4   120.1M(γ): While 2012Mu13 assign this as dipole and make no statement on its parity, its placement in the level scheme and the intensity of the 556.9-keV feeding γ-ray preclude an E1 assignment.
  4551.2   556.9M(γ): From α(exp) shown graphically in 1983It01
  4697.9   147M(γ): The intermediate DCO ratio suggests a mixed dipole/quadrupole transition. The presence of the parallel 546-keV transition complicates the analysis, but given the relatively intense feeding from the 398.6-keV γ-ray, an M1+E2 assignment seems most likely.
  5096.5   398.6M(γ): From α(exp) shown graphically in 1983It01.
  5354.5   258.0M(γ): Per 1983It01, the angular distribution for this γ-ray is consistent with a stretched quadrupole transition. Since it does not exhibit the long (≈100 ns) lifetime expected for an M2 transition, it is likely E2.
  5548.0   193.5M(γ): The DCO ratio suggests a mixed transition, and the feeding intensity of the 300.8-keV transition suggests it is not E1+M2.
  5848.8   300.8M(γ): Both the angular coefficients and the DCO ratio are somewhat difficult to interpret in this case, are consistent with the M1+E2 assignment suggested in 1983It01. This assignment is tentatively adopted lacking better evidence.
  6210.0   361.2M(γ): While 1983It01 suggests M1+E2 based on the small A2 angular coefficient, the DCO ratio measured in 2012Mu13 actually suggests a quadrupole transition, in which case this is most likely an E2 transition since it is not reported to have the expected long lifetime of an M2 decay.
  6643.6   433.6M(γ): 1983It01 suggests M1+E2 character for this transition based on the small A2 coefficient. The intermediate DCO ratio supports this assignment.

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