ADOPTED LEVELS for 264Sg

Author: Balraj Singh |  Citation: ENSDF |  Cutoff date: 25-Nov-2006 

Author: Y. A. Akovali |  Citation: Nucl. Data Sheets 87, 309 (1999) |  Cutoff date: 1-Nov-1998 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-5.3×103 keV SYS(n)= 7.5×103 keV SYS(p)= 3.6×103 keV SYQ(α)= 9.21×103 keV SY
Reference: 2012WA38

General Comments:

2006Gr24: 264Sg produced and identified in 238U(30Si,4n) reaction at E=148.7-173.1 MeV; 238UF4 rotating target at 88-Inch cyclotron facility at LBNL; Berkeley gas-filled recoil separator (BGS) of the LBNL. Evaporation residues recoiling from the target were separated by the BGS from the beam and other reaction products on the basis of magnetic rigidities in He gas. Measured SF decay and half-life. α total of five SF events were assigned to the decay of 264Sg. Assignment of these events to 4n channel is based on the fact that E30Si=148.7 MeV energy is below the threshold for 6n channel and only 4.7 MeV above the 5n threshold.

2006Ni10: 264Sg produced and identified in 238U(30Si,4n) at E=151.2 MeV. Rotating target wheel, SHIP-separator at GSI, position-sensitive Si strip (PIPS) detector, four Ge detectors for γ and x ray measurements, FWHM for α=25 keV. Four SF events assigned to 264Sg. From three events, the half-life of 120 ms +126-44 was deduced which is much longer than 37 ms +27-11 reported by 2006Gr24, although the production cross sections are comparable in the two studies.

Others:

1998Ik02: 238U(30Si,4n) E=158 MeV. Fission fragment spectrum measured using JAERI-RMS separator and position sensitive Si strip detector, FWHM for α=80 keV. From two SF events, T1/2= 54 s +98-21 assigned to 264Sg or 263Db. From studies of 2006Gr24 and 2006Ni10, it is clear that 1998Ik02 did not observe 264Sg, the fragments may be from 263Db which has half-life of a few seconds.

1981Ba08: angular distribution of fission fragments following 232Th(32S,X) fusion reaction at E=218 MeV was measured, and from the observed anisotropy of 2.96, deformation parameter of β(2)=0.35 was deduced for compound nucleus 264Sg.

For structure calculations and other theory references concerned 264Sg, consult NSR database at www.nndc.bnl.gov

Q-value: Note: Current evaluation has used the following Q record

Q-value: Δ(Q(β-))=400, Δ(S(n))=310, Δ(S(p))=330, Δ(Q(α))=200 (2003Au03)





E(level)
(keV)
Jπ(level) T1/2(level)
  0 0+ 37 ms +27-11 
% SF ≈ 100
% α < 36

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
  00+ 37 ms +27-11 
% SF ≈ 100
% α < 36
Cross section for production=9 pb +6-4 (2006Gr24) at excitation energy of the compound nucleus=39.3 MeV; 10 pb +10-6 (2006Ni10) at excitation energy of 40 MeV.
E(level): Cross section for production=9 pb +6-4 (2006Gr24) at excitation energy of the compound nucleus=39.3 MeV; 10 pb +10-6 (2006Ni10) at excitation energy of 40 MeV.

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