ADOPTED LEVELS for 254Md
Author: Balraj Singh | Citation: Nucl. Data Sheets 156, 1 (2019) | Cutoff date: 31-Jan-2019
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-1270 keV SY | S(n)= 5790 keV SY | S(p)= 3180 keV SY | Q(α)= 7800 keV SY | ||
| Reference: 2017WA10 |
| References: | |||
| A | 258Lr α decay (3.92 S) | ||
| E(level) (keV) | XREF | T1/2(level) |
| 0 | 10 m 3 % ε ≈ 100 | |
| 0+X | 28 m 8 % ε ≈ 100 | |
| 83 30 | A | |
| 114 30 | A | |
| 144 30 | A | |
| 175 30 | A |
E(level): Excited level energies are from 258Lr α decay. These levels should not be considered well established. See comments with the 258Lr α decay data.
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 10 m 3 % ε ≈ 100 | No α decays associated with 254Md decay could be identified by 1970Fi12. The authors pointed out that 254Fm and 256Md isotopes were also present in the source, and any α branches from 254Md would be indistinguishable since they would fall in the energy region of main α branches from 254Fm and 256Md decays. E(level): No α decays associated with 254Md decay could be identified by 1970Fi12. The authors pointed out that 254Fm and 256Md isotopes were also present in the source, and any α branches from 254Md would be indistinguishable since they would fall in the energy region of main α branches from 254Fm and 256Md decays. | |
| 0+X | 28 m 8 % ε ≈ 100 | No α decay from this state could be identified (1970Fi12). E(level): No α decay from this state could be identified (1970Fi12). |
Assignment: 253Es(46-MeV 4He,3n); chemistry, parent of 254Fm (1970Fi12)
Both the known activities of 254Md decay almost 100% by β+,ε decays, but no experimental data are available for details of the two decays and level structure in 254Fm. Based on particle plus rotor model phenomenological calculations, 2017So07 analyzed β++ε decays of the 10-min and 28-min activities of 254Md to 254Fm, and concluded that 10-min activity, assigned as π1/2[521]~#ν1/2[620], Kπ=0-, Jπ=1- is the ground state, and the 28-min activity, assigned as π7/2[514]~#ν1/2[620], Kπ=3-, Jπ=3- isomer lying within a few keV of the 10-min ground state.
1986So12: calculated levels, bandhead energies, Kπ, isomer T1/2
Levels: For the g.s. configuration, analogy to 255Md and to 257Md suggests π7/2[514] orbital for the 101Th proton and analogy to 251Cf and to 249Cm suggests ν1/2[620] orbital for the 153rd neutron. Energies of the π1/2[521] and the ν 7/2[613] Nilsson states should be low. Combinations of these quasiparticle states suggests the following possible configurations for the g.s. and low-energy states: 3-, π7/2[514]~#ν1/2[620]; 4-, π7/2[514]~#ν1/2[620]; 3-, π1/2[521]~#ν7/2[613]; 4-, π1/2[521]~#ν7/2[613]; 0-, π7/2[514]~#ν7/2[613]; 7-, π7/2[514]~#ν7/2[613]; 0-, π1/2[521]~#ν1/2[620]; 1-, π1/2[521]~#ν1/2[620]
Q-value: Estimated uncertainties (2017Wa10): 100 for Q(β-) and S(p), 110 for S(n), 140 for Q(α)
Q-value: S(2n)=13200 160, S(2p)=8420 110 (syst,2017Wa10)