ADOPTED LEVELS, GAMMAS for 251Fm
Author: C. Morse | Citation: Nucl. Data Sheets 189, 111 (2023) | Cutoff date: 23-Sep-2022
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-3008 keV 24 | S(n)= 6185 keV 16 | S(p)= 4555 keV SY | Q(α)= 7424.5 keV 10 | ||
| Reference: 2021Wa16 |
| References: | |||
| A | 255No α decay | ||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
| 0 | A | (9/2-) | 5.30 h 8 % α = 1.80 13 | |||||
| 63.9 8 | A | (11/2-) | 63.9 8 | 100 | M1 | 0 | (9/2-) | |
| 200.07 10 | A | (5/2+) | 22.9 µs 9 | 200.07 10 | 100 | M2+E3 | 0 | (9/2-) |
| 243 3 | A | (7/2+) | ||||||
| 301 3 | A | (9/2+) | ||||||
| 353.8 3 | A | (7/2+) | 353.8 3 | 100 | (E1) | 0 | (9/2-) | |
| 391.97 16 | A | (1/2+) | 22 ns 3 | 191.95 14 | 100 | E2 | 200.07 | (5/2+) |
| 395.27 22 | A | (3/2+) | < 16 ns | 3.4S 195.2 3 | 100 | [M1] M1 | 391.97 200.07 | (1/2+) (5/2+) |
| 461 3 | A | (5/2+) | ||||||
| 558.57 17 | A | (1/2+) | < 8 ns | 163.3 2 166.7 2 358.4 2 | 35 9 16 6 100 | M1 M1 E2 | 395.27 391.97 200.07 | (3/2+) (1/2+) (5/2+) |
| 579 5 | A | (3/2+) | ||||||
| 604 4 | A | (5/2+) | ||||||
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
| Band 1 - ν9/2-[734] | |||||||
| 0 | (9/2-) | 5.30 h 8 % α = 1.80 13 | |||||
| 63.9 8 | (11/2-) | 63.9 8 | 100 | M1 | 0 | (9/2-) | |
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
| Band 2 - ν5/2+[622] | |||||||
| 200.07 10 | (5/2+) | 22.9 µs 9 | |||||
| 243 3 | (7/2+) | ||||||
| 301 3 | (9/2+) | ||||||
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
| Band 3 - ν1/2+[631] | |||||||
| 391.97 16 | (1/2+) | 22 ns 3 | |||||
| 395.27 22 | (3/2+) | < 16 ns | 3.4S 195.2 3 | 100 | [M1] M1 | 391.97 200.07 | (1/2+) (5/2+) |
| 461 3 | (5/2+) | ||||||
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
| Band 4 - ν1/2+[620] | |||||||
| 558.57 17 | (1/2+) | < 8 ns | |||||
| 579 5 | (3/2+) | ||||||
| 604 4 | (5/2+) | ||||||
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) (keV) | Multipolarity | Mixing Ratio | Conversion Coefficient | Additional Data |
| 63.9 | (11/2-) | 63.9 8 | M1 | 38.7 | α=38.7 16, α(L)=28.9 12, α(M)=7.2 3, α(N)=2.00 8, α(O)=0.528 22, α(P)=0.103 5, α(Q)=0.00579 24 | ||
| 200.07 | (5/2+) | 22.9 µs 9 | 200.07 10 | M2+E3 | 0.76 +20-19 | 20.9 | B(E3)(W.u.)=19 7, B(M2)(W.u.)=0.0031 7, α=20.9 10, α(K)=9.3 18, α(L)=8.3 6, α(M)=2.41 19, α(N)=0.69 6, α(O)=0.179 14, α(P)=0.0315 19, α(Q)=0.00095 13 |
| 353.8 | (7/2+) | 353.8 3 | (E1) | 0.0342 | α=0.0342, α(K)=0.0266 4, α(L)=0.00567 8, α(M)=0.001391 20, α(N)=0.000386 6, α(O)=0.0001003 15, α(P)=1.84×10-5 3, α(Q)=8.24E-7 12 | ||
| 391.97 | (1/2+) | 22 ns 3 | 191.95 14 | E2 | 1.567 | B(E2)(W.u.)=0.41 6, α=1.567, α(K)=0.1385 20, α(L)=1.027 15, α(M)=0.293 5, α(N)=0.0833 12, α(O)=0.0211 3, α(P)=0.00346 5, α(Q)=2.49E-5 4 | |
| 395.27 | (3/2+) | < 16 ns | 3.4 | [M1] | 1.599×104 | α=1.599×104, α(N)=1.211E4 17, α(O)=3.22E3 5, α(P)=625 9, α(Q)=35.5 5 | |
| (3/2+) | < 16 ns | 195.2 3 | M1 | 6.83 | B(M1)(W.u.)=2.4×10-5 GT, α=6.83, α(K)=5.29 8, α(L)=1.152 17, α(M)=0.284 5, α(N)=0.0794 12, α(O)=0.0210 3, α(P)=0.00407 6, α(Q)=0.000228 4 | ||
| 558.57 | (1/2+) | < 8 ns | 163.3 2 | M1 | 11.30 | B(M1)(W.u.)=3.0×10-5 GT, α=11.30, α(K)=8.74 13, α(L)=1.91 3, α(M)=0.473 7, α(N)=0.1320 19, α(O)=0.0349 5, α(P)=0.00677 10, α(Q)=0.000379 6 | |
| (1/2+) | < 8 ns | 166.7 2 | M1 | 10.66 | B(M1)(W.u.)=1.3×10-5 GT, α=10.66, α(K)=8.25 12, α(L)=1.80 3, α(M)=0.446 7, α(N)=0.1245 18, α(O)=0.0329 5, α(P)=0.00638 10, α(Q)=0.000357 6 | ||
| (1/2+) | < 8 ns | 358.4 2 | E2 | 0.181 | B(E2)(W.u.)=0.017 GT, α=0.181, α(K)=0.0651 10, α(L)=0.0843 12, α(M)=0.0235 4, α(N)=0.00664 10, α(O)=0.001698 24, α(P)=0.000290 4, α(Q)=4.57E-6 7 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | (9/2-) | 5.30 h 8 % α = 1.80 13 | CONF=|n9/2-[734] (2011As03) E(level): ν9/2-[734]. |
| 63.9 | (11/2-) | E(level): ν9/2-[734]. | |
| 200.07 | (5/2+) | 22.9 µs 9 | CONF=|n5/2+[622] (2011As03) E(level): ν5/2+[622]. |
| 243 | (7/2+) | E(level): ν5/2+[622]. | |
| 301 | (9/2+) | E(level): ν5/2+[622]. | |
| 391.97 | (1/2+) | 22 ns 3 | CONF=|n1/2+[631] (2011As03) E(level): ν1/2+[631]. |
| 395.27 | (3/2+) | < 16 ns | E(level): ν1/2+[631]. |
| 461 | (5/2+) | E(level): ν1/2+[631]. | |
| 558.57 | (1/2+) | < 8 ns | CONF=|n1/2+[620] (2011As03) E(level): ν1/2+[620]. |
| 579 | (3/2+) | E(level): ν1/2+[620]. | |
| 604 | (5/2+) | E(level): ν1/2+[620]. |
$ Unless otherwise noted, all data are from 255No α decay. Spins, parities, and configurations of levels are those assigned in 2011As03, primarily based on α-decay hindrance factors and γ-ray decay patterns.
$ Mass measurement: 2018It04.
Q-value: ΔS(p)=101 (2021Wa16)
Q-value: S(2n)=13703 16, S(2p)=8342 14 (2021Wa16)