ADOPTED LEVELS, GAMMAS for 251Fm
Authors: E. Browne, J. K. Tuli | Citation: Nucl. Data Sheets 114, 1041 (2013) | Cutoff date: 1-Jan-2012
Full ENSDF file | Adopted Levels (PDF version)
Q(β-)=-3013 keV 24 | S(n)= 6190 keV 17 | S(p)= 4562 keV SY | Q(α)= 7425.1 keV 20 | ||
Reference: 2012WA38 |
References: | |||
A | 255No α decay |
E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
0.0 | A | (9/2-) | 5.30 h 8 % ε = 98.20 13 % α = 1.80 13 | |||||
63.9 8 | A | 11/2- | 63.9 8 | 100 | M1 | 0.0 | (9/2-) | |
200.0 1 | A | 5/2+ | 21.1 µs 19 | 200.0 1 | 100 | M2 | 0.0 | (9/2-) |
243 3 | A | 7/2+ | ||||||
301 3 | A | 9/2+ | ||||||
353.9 4 | A | (7/2+) | 353.9 4 | 100 | [E1] | 0.0 | (9/2-) | |
391.8 2 | A | 1/2+ | 22 ns 3 | 192.0 2 | 100 | (E2) | 200.0 | 5/2+ |
395.05 18 | A | 3/2+ | < 16 ns | 3.4 3 S 194.9 2 | 100 | [M1] M1 | 391.8 200.0 | 1/2+ 5/2+ |
461 3 | A | 5/2+ | ||||||
558.43 18 | A | 1/2+ | < 8 ns | 163.3 2 166.7 2 358.4 2 | 35 9 16 6 100 20 | (M1) [M1] [E2] | 395.05 391.8 200.0 | 3/2+ 1/2+ 5/2+ |
579 5 | A | 3/2+ | ||||||
604 4 | A | 5/2+ |
E(level): From 255No α decay
Jπ(level): Assignments of Jπ and rotational bands are those proposed in 2011As03. They are based on analogy with n=151 nuclei (249Cf and 247Cm) and rotational structure, on γ-ray multipolarities, and α-decay hindrance factors.
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 1 - ROTATIONAL band ν9/2[734] | |||||||
0.0 | (9/2-) | 5.30 h 8 % ε = 98.20 13 % α = 1.80 13 | |||||
63.9 8 | 11/2- | 63.9 8 | 100 | M1 | 0.0 | (9/2-) | |
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) | I(γ) | M(γ) | Final Levels | |
Band 2 - ROTATIONAL band ν5/2[622] | |||||||
200.0 1 | 5/2+ | 21.1 µs 19 | |||||
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 - ROTATIONAL band ν1/2[631] | |||||||
391.8 2 | 1/2+ | 22 ns 3 | |||||
395.05 18 | 3/2+ | < 16 ns | 3.4 3 S 194.9 2 | 100 | [M1] M1 | 391.8 200.0 | 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 - ROTATIONAL band ν1/2[620] | |||||||
558.43 18 | 1/2+ | < 8 ns | |||||
579 5 | 3/2+ | ||||||
604 4 | 5/2+ |
E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) (keV) | Multipolarity | 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, α(N+)=2.64 11 | |
200.0 | 5/2+ | 21.1 µs 19 | 200.0 1 | M2 | 23.8 | B(M2)(W.u.)=0.0047 5, α=23.8, α(K)=14.49 21, α(L)=6.75 10, α(M)=1.85 3, α(N)=0.528 8, α(O)=0.1393 20, α(P)=0.0261 4, α(Q)=0.001339 19, α(N+)=0.695 10 |
353.9 | (7/2+) | 353.9 4 | [E1] | 0.0342 | α=0.0342, α(K)=0.0266 4, α(L)=0.00566 8, α(M)=0.001390 20, α(N)=0.000386 6, α(O)=0.0001002 15, α(P)=1.84×10-5 3, α(Q)=8.23E-7 12, α(N+)=0.000505 8 | |
391.8 | 1/2+ | 22 ns 3 | 192.0 2 | (E2) | 1.565 | B(E2)(W.u.)=0.41 6, α=1.565, α(K)=0.1385 20, α(L)=1.026 15, α(M)=0.293 5, α(N)=0.0832 13, α(O)=0.0211 4, α(P)=0.00346 5, α(Q)=2.49E-5 4, α(N+)=0.1078 16 |
395.05 | 3/2+ | < 16 ns | 3.4 3 | [M1] | 1.6×104 | α=1.6×104 5, α(N)=1.2E4 4, α(O)=3.2E3 11, α(P)=6.2E2 20, α(Q)=36 12, α(N+)=1.6E4 5 |
3/2+ | < 16 ns | 194.9 2 | M1 | 6.86 | B(M1)(W.u.)>2.3×10-5, α=6.86, α(K)=5.31 8, α(L)=1.157 17, α(M)=0.286 4, α(N)=0.0798 12, α(O)=0.0211 3, α(P)=0.00409 6, α(Q)=0.000229 4, α(N+)=0.1052 15 | |
558.43 | 1/2+ | < 8 ns | 163.3 2 | (M1) | 11.30 | B(M1)(W.u.)>3.0×10-5, 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, α(N+)=0.174 3 |
1/2+ | < 8 ns | 166.7 2 | [M1] | 10.66 | B(M1)(W.u.)>1.3×10-5, 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, α(N+)=0.1641 24 | |
1/2+ | < 8 ns | 358.4 2 | [E2] | 0.181 | B(E2)(W.u.)>0.017, 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, α(N+)=0.00863 13 |
Additional Level Data and Comments:
E(level) | Jπ(level) | T1/2(level) | Comments |
0.0 | (9/2-) | 5.30 h 8 % ε = 98.20 13 % α = 1.80 13 | E(level): ROTATIONAL band ν9/2[734]. |
63.9 | 11/2- | E(level): ROTATIONAL band ν9/2[734]. | |
200.0 | 5/2+ | 21.1 µs 19 | E(level): ROTATIONAL band ν5/2[622]. |
243 | 7/2+ | E(level): ROTATIONAL band ν5/2[622]. | |
301 | 9/2+ | E(level): ROTATIONAL band ν5/2[622]. | |
391.8 | 1/2+ | 22 ns 3 | E(level): ROTATIONAL band ν1/2[631]. |
395.05 | 3/2+ | < 16 ns | E(level): ROTATIONAL band ν1/2[631]. |
461 | 5/2+ | E(level): ROTATIONAL band ν1/2[631]. | |
558.43 | 1/2+ | < 8 ns | E(level): ROTATIONAL band ν1/2[620]. |
579 | 3/2+ | E(level): ROTATIONAL band ν1/2[620]. | |
604 | 5/2+ | E(level): ROTATIONAL band ν1/2[620]. |
E(level) | E(gamma) | Comments |
395.05 | 3.4 | E(γ): existence of this transition is suggested in 2011As03 from the intensity imbalances between the 191.91-166.7 keV cascade and the 195.3-163.3 keV γγ cascades (2011As03). |
Calculations, compilations:
Favored α decays: 1992Bu03, 1993Bu09, 2003Re32
Ground state properties: 1997Mo25, 1995Mo29
2005Pa73: Calculated deformation, pairing.
Single-particle Nilsson levels: 2006Sh19, 2005Pa73, 1994Cw02
SF Half-life: 2005Re16
Q(α), T1/2: 2012Po01, 2011He12, 2011Zh36, 2010Ni02, 2010Si27, 2009Do22, 2009Sa25, 2008Do12, 2005Ga25, 2003Re32
Neutron Separation Energies: 2004Pa31
1994Cw02 calculated the following single-particle level sequence: g.s. 9/2[734], 0.21 MeV 7/2[624], 0.44 MeV 5/2[622], 0.65 MeV 1/2[620], 0.79 MeV 3/2[622], 0.89 MeV 7/2[613], 1.03 MeV 11/2[725]
Assignment: 249Cf(α,2n) chem, excit (1957Am47,1973Ah02)
Q-value: Estimated ΔS(p)=101 (2012Wa38)