ADOPTED LEVELS for 254Lr
Author: Balraj Singh | Citation: Nucl. Data Sheets 156, 1 (2019) | Cutoff date: 31-Jan-2019
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-3330 keV SY | S(n)= 6780 keV SY | S(p)= 1780 keV SY | Q(α)= 8816 keV 12 | ||
| Reference: 2017WA10 |
| References: | |||
| A | 258Db α decay (4.3 S) | B | 258Db α decay (1.9 S) |
| E(level) (keV) | XREF | T1/2(level) |
| 0 | A | 18.1 s 18 % ε = 28.3 19 % α = 71.7 19 % SF < 0.1 |
| 0+X? | B | % ε = ? % α = ? |
| 74 50 | A | |
| 190 50 | A | |
| 222 50 | A | |
| 248 50 | A | |
| 268 50 | A | |
| 344 50 | A |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 18.1 s 18 % ε = 28.3 19 % α = 71.7 19 % SF < 0.1 | Upper limit for SF decay mode: see details in 2000Ho27 evaluation. E(level): Upper limit for SF decay mode: see details in 2000Ho27 evaluation. | |
| 0+X | % ε = ? % α = ? | From the decays of two α-activities in 258Db, 2009He20 assumed two long-lived activities in 254Lr, but two separate half-lives for 254Lr could not be determined. E(level): From the decays of two α-activities in 258Db, 2009He20 assumed two long-lived activities in 254Lr, but two separate half-lives for 254Lr could not be determined. |
1981Mu06: 254Lr identified as daughter of 258Db and grand-daughter of 262Bh, which were produced in 209Bi(54Cr,n), E=4.85 MeV/nucleon; and 209Bi(50Ti,n), E=4.75 MeV/nucleon reactions at GSI, measured half-life. Later measurements were made at the same laboratory and reported in 1985He22, 1989Mu09 and 2008An16
1984Og03: 254Lr produced and identified in 208Pb(48Ti,pn) reaction, and assignment made through α decay chain, as grandparent of 246Cf through the 6750α.
Theoretical studies: consult the NSR database at www.nndc.bnl.gov for 23 references dealing with theoretical calculations of half-lives for different decay modes, binding energies, fission characteristics, and other nuclear structure aspects.
Levels: The deduced HF values for the observed α transitions are larger than 25, indicating that none of these α transitions are favored, therefore, the data indicate that the main configurations of these excited states are not identical to that of 258Db g.s.
Q-value: Estimated uncertainties (2017Wa10): 410 for Q(β-), 360 for S(n), 300 for S(p).
Q-value: S(2n)=15010 380, S(2p)=5220 330, Q(εp)=1410 300 (syst,2017Wa10)
Q-value: 2018It04 deduced mass excess(254Lr)=89713 keV 141 using Q(α) from 2017Wa10, where mass excess=89871 keV 301 from systematics.