Author: Balraj Singh |  Citation: Nucl. Data Sheets 144, 297 (2017) |  Cutoff date: 25-Aug-2017 

 Full ENSDF file | Adopted Levels (PDF version) 

Q(β-)=-1260 keV SYS(n)= 6240 keV SYS(p)= 6270 keV SYQ(α)= 6660 keV SY
Reference: 2017WA10

  A  258Md ε decay (57.0 M) 

General Comments:

1971Hu03: 258Fm produced in 257Fm(d,p), measured T1/2(SF)

1971Jo13: 258Fm from thermal neutron capture in 257Fm, studied SF distribution

1986Hu05: 258Fm from ε-decay daughter of 57-min 258Md; measured time correlation of fermium K-x rays with SF fragments

1989Hu09, 1986Hu01, 1980Ho04: measured fission-fragment mass and total kinetic energy distributions

Theoretical studies: consult the NSR database at for about 120 references dealing with theoretical calculations of half-lives for different decay modes, binding energies, fission characteristics, and other nuclear structure aspects.

Q-value: Estimated uncertainties (2017Wa10): 200 for Q(β-), S(n) and Q(α), 460 for S(p)

Q-value: S(2n)=11200 200, S(2p)=11190 370 (syst,2017Wa10)

XREFJπ(level) T1/2(level)
  0A 0+ 370 µs 14 
% SF ≈ 100

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Additional Level Data and Comments:

  00+ 370 µs 14 
% SF ≈ 100
Theoretical partial half-lives for α decay predict very small α branch: T1/2(α)=12.9 y (1997Mo25), 86 d (1997Po18).

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