Author: Balraj Singh |  Citation: Nucl. Data Sheets 156, 148 (2019) |  Cutoff date: 31-Jan-2019 

 Full ENSDF file | Adopted Levels (PDF version) 

S(n)= 7790 keV CAS(p)= 3070 keV SYQ(α)= 10800 keV SY
Reference: 2017WA10,1997MO25

General Comments:

2015Ut02: 284Fl identified in 239Pu,240Pu(48Ca,4n), E=245,250 MeV at U400 cyclotron of FLNR-JINR facility. Targets=240Pu enriched to 98.97% at ORNL facility, and 92% enriched at JINR facility, with average thickness of 0.39 mg/cm2 4 for mixed ORNL/JINR 240Pu material. Evaporation residues (ERs) were separated from the incident beam ions, scattered particles, and transfer reaction products by the DGFRS based on magnetic rigidities. Recoils passed through a tof system of two multiwire proportional counters (MWPCs), and were implanted in the DSSD detector system (0.3-mm thick double-sided silicon strip detectors) placed at the final focus of the DGFRS. Events related to Z=114 were identified by detecting time and position correlated events corresponding to their implantation and subsequent SF decay; EVR-SF correlations. Five events were observed, four in 240Pu(48Ca,4n) reaction and one in 239Pu(48Ca,3n) reaction.

2015Ut02 discuss observation of three SF events with low energies and decay times of 16.3, 16.9 and 55.3 μs, which may correspond to SF isomers, but based on implantation energy and average decay half-life of 19 μs, authors conclude that these activities most likely originate from other nuclides.

2018Ut02: 240Pu(48Ca,4n),E=250 MeV at JINR-Dubna. Several SF decays with measured evaporation residue energy, decay time, and SF energy assigned to the decay of 284Fl from three observed events, and other eight events with 1-ms activity could belong to 284Fl or 282Cn, the latter through α2n-channel

Note that the 284Fl nuclide is reported by only the Dubna group. An independent observation by another experimental group is needed for a confirmed existence of this nuclide.

For theoretical studies, consult Nuclear Science References (NSR) database at NNDC, BNL for 62 primary references dealing with the half-lives and other aspects of nuclear structure in this mass region

Q-value: Estimated uncertainties (2017Wa10): ΔS(p)=930, ΔQ(α)=300.

Q-value: S(p) and Q(α) from 2017Wa10, S(n) from 1997Mo25.

Q-value: S(2p)=4630 930, Q(ε)=150 900 (syst, 2017Wa10). S(2n)=14300 (theory,1997Mo25)

Jπ(level) T1/2(level)
  0 0+ 2.5 ms +18-8 
% SF = 100
% α ≤ 25

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Additional Level Data and Comments:

  00+ 2.5 ms +18-8 
% SF = 100
% α ≤ 25
Only the SF decay mode has been observed.
E(level): Only the SF decay mode has been observed.

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