ADOPTED LEVELS, GAMMAS for 256Fm
Author: Balraj Singh | Citation: Nucl. Data Sheets 141, 327 (2017) | Cutoff date: 22-Mar-2017
Full ENSDF file | Adopted Levels (PDF version)
Q(β-)=-1970 keV SY | S(n)= 6384 keV 7 | S(p)= 5891 keV 12 | Q(α)= 7027 keV 5 | ||
Reference: 2017WA10 |
References: | |||
A | 256Es β- decay (25.4 M) | B | 256Es β- decay (7.6 H) |
C | 256Md ε decay (77.7 M) |
E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
0.0 | BC | 0+ | 157.1 m 13 % α = 8.1 3 % SF = 91.9 3 | |||||
48.12 16 | BC | 2+ | 48.3 3 S | | [E2] | 0.0 | 0+ | |
159.60 20 | BC | 4+ | 111.6 2 | 100 | [E2] | 48.12 | 2+ | |
332.2 3 | B | 6+ | 172.6 2 | 100 | [E2] | 159.60 | 4+ | |
563.3 3 | B | 8+ | 231.1 2 | 100 | [E2] | 332.2 | 6+ | |
682.21 14 | BC | (2+) | 634.1 2 682.2 2 | 94 10 100 | 48.12 0.0 | 2+ 0+ | ||
725.43 19 | BC | (3+) | 565.9 3 677.4 2 | 23 4 100 8 | 159.60 48.12 | 4+ 2+ | ||
783.20 22 | B | (4+) | 450.8 15 623.5 2 | 13 100 | 332.2 159.60 | 6+ 4+ | ||
853.4 5 | B | (5+) | 693.8 15 | 100 | 159.60 | 4+ | ||
881.59 19 | B | (2-) | 156 2 199.3 2 833.5 2 | 1.5 26 100 | 725.43 682.21 48.12 | (3+) (2+) 2+ | ||
922.03 23 | B | (3-) | 141 2 197.4 5 ? 762.7 2 | 4 35 100 | 783.20 725.43 159.60 | (4+) (3+) 4+ | ||
938.8 16 | B | (6+) | 606.6 15 | 100 | 332.2 | 6+ | ||
978.1 5 | B | (4-) | 252.7 5 | 100 | 725.43 | (3+) | ||
1039.0 4 | B | (7+) | 185.7 5 706.8 2 | 22 100 | 853.4 332.2 | (5+) 6+ | ||
1045.1 5 | B | (5-) | 67.0S 192 2 | | 978.1 853.4 | (4-) (5+) | ||
1099.73 18 | B | (3+) | 178.0 2 218.1 2 316.4 2 374.2 2 417.6 2 940.1 15 1051.5 2 | ≤19 100 18 25 27 14 45 | 922.03 881.59 783.20 725.43 682.21 159.60 48.12 | (3-) (2-) (4+) (3+) (2+) 4+ 2+ | ||
E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
1123.0 5 | B | (6-) | 78.0S 269.5 5 | | 1045.1 853.4 | (5-) (5+) | ||
1150.3? | B | (8+) | 211.2 5 ? 586.6 15 ? | | 938.8 563.3 | (6+) 8+ | ||
1150.4 4 | B | (4+) | 50.8S | | 1099.73 | (3+) | ||
1213.5 11 ? | B | (7-) | 90.5S | | 1123.0 | (6-) | ||
1251.6 4 | B | (5+) | 397.2 5 ? 468.4 5 526.1 5 | 82 100 91 | 853.4 783.20 725.43 | (5+) (4+) (3+) | ||
1326.17 18 | C | (1+) | 600.8 4 644.0 2 1278.0 3 1326.1 3 | 17 3 100 8 14 2 33 3 | 725.43 682.21 48.12 0.0 | (3+) (2+) 2+ 0+ | ||
1328.3 4 ? | B | (6+) | 76.8S 178.0 2 | | 1251.6 1150.4 | (5+) (4+) | ||
1360.4 3 | C | (2+) | 634.1 2 ? 677.3 2 ? 1200.6 5 1312.3 3 | 76 30 42 9 100 9 | 725.43 682.21 159.60 48.12 | (3+) (2+) 4+ 2+ | ||
1374.19 18 | C | (1-) | 692.0 2 1326.1 3 1374.1 3 | 100 8 49 4 52 6 | 682.21 48.12 0.0 | (2+) 2+ 0+ | ||
1405.27 21 | C | (2-) | 680.0 3 723.0 2 1357.1 3 | 70 6 82 9 100 9 | 725.43 682.21 48.12 | (3+) (2+) 2+ | ||
1425.1 3 | B | (7-) | 70 ns 5 % IT = 100 | 96.8 2 211.2 5 ? 275.3 2 ? 302.0 5 380.0 5 861.8 2 1092.9 2 | 13 ≤4.4 5.8 4.2 1.9 100 47 | 1328.3 1213.5 1150.3 1123.0 1045.1 563.3 332.2 | (6+) (7-) (8+) (6-) (5-) 8+ 6+ | |
E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
1559.8 4 | B | (7+,8+) | 134.7 2 | 100 | [E1] | 1425.1 | (7-) |
E(level): From least-squares fit to Eγ values
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 1 - Kπ=0+ band. | |||||||
0.0 | 0+ | 157.1 m 13 % α = 8.1 3 % SF = 91.9 3 | |||||
48.12 16 | 2+ | 48.3 3 S | | [E2] | 0.0 | 0+ | |
159.60 20 | 4+ | 111.6 2 | 100 | [E2] | 48.12 | 2+ | |
332.2 3 | 6+ | 172.6 2 | 100 | [E2] | 159.60 | 4+ | |
563.3 3 | 8+ | 231.1 2 | 100 | [E2] | 332.2 | 6+ | |
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 2 - Kπ=(2+) γ-vibrational band. | |||||||
682.21 14 | (2+) | ||||||
725.43 19 | (3+) | 565.9 3 677.4 2 | 23 4 100 8 | 159.60 48.12 | 4+ 2+ | ||
783.20 22 | (4+) | 450.8 15 623.5 2 | 13 100 | 332.2 159.60 | 6+ 4+ | ||
853.4 5 | (5+) | 693.8 15 | 100 | 159.60 | 4+ | ||
938.8 16 | (6+) | 606.6 15 | 100 | 332.2 | 6+ | ||
1039.0 4 | (7+) | 185.7 5 706.8 2 | 22 100 | 853.4 332.2 | (5+) 6+ | ||
1150.3 | (8+) | 211.2 5 ? 586.6 15 ? | | 938.8 563.3 | (6+) 8+ | ||
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 3 - Kπ=(2-) octupole-vibrational band. | |||||||
881.59 19 | (2-) | ||||||
922.03 23 | (3-) | 141 2 197.4 5 ? 762.7 2 | 4 35 100 | 783.20 725.43 159.60 | (4+) (3+) 4+ | ||
978.1 5 | (4-) | 252.7 5 | 100 | 725.43 | (3+) | ||
1045.1 5 | (5-) | 67.0S 192 2 | | 978.1 853.4 | (4-) (5+) | ||
1123.0 5 | (6-) | 78.0S 269.5 5 | | 1045.1 853.4 | (5-) (5+) | ||
1213.5 11 | (7-) | 90.5S | | 1123.0 | (6-) | ||
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 4 - Kπ=(3+) band | |||||||
1099.73 18 | (3+) | ||||||
1150.4 4 | (4+) | 50.8S | | 1099.73 | (3+) | ||
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 5 - Kπ=(5+) band | |||||||
1251.6 4 | (5+) | ||||||
1328.3 4 | (6+) | 76.8S 178.0 2 | | 1251.6 1150.4 | (5+) (4+) |
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) (keV) | Multipolarity | Conversion Coefficient | Additional Data |
48.12 | 2+ | 48.3 3 | [E2] | 832 | α=832 | |
159.60 | 4+ | 111.6 2 | [E2] | 15.96 | α=15.96 | |
332.2 | 6+ | 172.6 2 | [E2] | 2.40 | α=2.40 | |
563.3 | 8+ | 231.1 2 | [E2] | 0.772 | α=0.772 | |
1559.8 | (7+,8+) | 134.7 2 | [E1] | 0.0735 | α=0.0735 |
Additional Level Data and Comments:
E(level) | Jπ(level) | T1/2(level) | Comments |
0.0 | 0+ | 157.1 m 13 % α = 8.1 3 % SF = 91.9 3 | Branching: α/(α+SF)=0.081 3 was determined by 1968Ho13 from α and SF counts. Other measurement: SF/α=35 10 (1965Si14). E(level): Branching: α/(α+SF)=0.081 3 was determined by 1968Ho13 from α and SF counts. Other measurement: SF/α=35 10 (1965Si14). Kπ=0+ band. |
48.12 | 2+ | E(level): Kπ=0+ band. Jπ(level): Strong evidence for the presence of rotational band based on g.s. | |
159.60 | 4+ | E(level): Kπ=0+ band. Jπ(level): Strong evidence for the presence of rotational band based on g.s. | |
332.2 | 6+ | E(level): Kπ=0+ band. Jπ(level): Strong evidence for the presence of rotational band based on g.s. | |
563.3 | 8+ | E(level): Kπ=0+ band. Jπ(level): Strong evidence for the presence of rotational band based on g.s. | |
682.21 | (2+) | E(level): Kπ=(2+) γ-vibrational band. | |
725.43 | (3+) | E(level): Kπ=(2+) γ-vibrational band. | |
783.20 | (4+) | E(level): Kπ=(2+) γ-vibrational band. | |
853.4 | (5+) | E(level): Kπ=(2+) γ-vibrational band. | |
881.59 | (2-) | E(level): Kπ=(2-) octupole-vibrational band. | |
922.03 | (3-) | E(level): Kπ=(2-) octupole-vibrational band. | |
938.8 | (6+) | E(level): Kπ=(2+) γ-vibrational band. | |
978.1 | (4-) | E(level): Kπ=(2-) octupole-vibrational band. | |
1039.0 | (7+) | E(level): Kπ=(2+) γ-vibrational band. | |
1045.1 | (5-) | E(level): Kπ=(2-) octupole-vibrational band. | |
1099.73 | (3+) | E(level): Kπ=(3+) band. | |
1123.0 | (6-) | E(level): Kπ=(2-) octupole-vibrational band. | |
1150.3 | (8+) | E(level): Kπ=(2+) γ-vibrational band. | |
1150.4 | (4+) | E(level): Kπ=(3+) band. | |
1213.5 | (7-) | E(level): Kπ=(2-) octupole-vibrational band. | |
1251.6 | (5+) | E(level): Kπ=(5+) band. | |
1326.17 | (1+) | Proposed configuration=ν7/2[613]~#ν9/2[615] (2000Ah02). | |
1328.3 | (6+) | E(level): Kπ=(5+) band. | |
1360.4 | (2+) | Proposed configuration=ν7/2[613]~#ν9/2[615] (2000Ah02). | |
1374.19 | (1-) | Proposed configuration=π7/2[633]~#π7/2[514] (2000Ah02). | |
E(level) | Jπ(level) | T1/2(level) | Comments |
1405.27 | (2-) | Proposed configuration=π7/2[633]~#π7/2[514] (2000Ah02). | |
1425.1 | (7-) | 70 ns 5 % IT = 100 | The partial half-life for fission was deduced by 1989Ha10 as 0.8 ms +88-7 from the β-delayed-fission probability of 2×10-5 (measured number of delayed fissions/total number of β- decays of 7.6H 256Es; two fission events were observed.). |
1955Ch30 produced and identified 256Fm in neutron irradiation of 255Es, and β- decay of 256Es at Berkeley. Measured half-life from decay curve for spontaneous fission. Later studies: of 256Fm decay: 1958Ph40, 1965Si14, 1968Ho13, 1972Fl04, 1981Lo15
Theoretical calculations: consult the Nuclear Science References (NSR) database for about 200 theory references.
2014Sh07, 2013Af01, 2013Pr08, 2012Jo05: nuclear structure theory references
Levels: Assignments to band members are from depopulation patterns, and energy fit to rotational bands.
Q-value: Estimated uncertainty=120 for Q(β-) (2017Wa10)
Q-value: S(2n)=11559 7, S(2p)=10433 12 (2017Wa10)