Author: Balraj Singh |  Citation: ENSDF |  Cutoff date: 18-DEC-2015 

Authors: Sukhjeet Singh, A. K. Jain, Jagdish K. Tuli |  Citation: Nucl. Data Sheets 112,2851 (2011) |  Cutoff date: 31-Mar-2011 

 Full ENSDF file | Adopted Levels (PDF version) 

Q(β-)=-6800 keV SYS(n)= 8330 keV SYS(p)= 3440 keV SYQ(α)= 9430 keV SY
Reference: 2012WA38

General Comments:

1983Hi12: W(40Ar,xn) E=180 MeV; products were separated from the primary beam by the velocity filter; parent of 214Ra (7.16-MeV α). Tentative identification of 222U nuclide.

2015Kh09: 222U produced and identified in 176Yb(50Ti,4n), E(50Ti=231-255 MeV reaction. The 50Ti12+ pulsed beam was produced by the UNILAC at GSI. Target=0.45 mg/cm2 5 thick 176YbF3 mounted on a rotating wheel, synchronized with the beam pulses. Evaporation residues (Er), separated by using gas-filled TransActinide Separator and Chemistry Apparatus (TASCA) with flight time of 0.53 μs 6 through the separator, were implanted in a double-sided silicon strip detector. The events due to radioactive decays of implanted residues were selected from the events related to beam using a multiwire proportional counter (MWPC). Measured Eα, Iα, Er-α correlated events from subsequent α-decay chains, half-lives of parent nuclei corresponding to the evaporation residues, and successive α-decay daughters, the latter identified by their known characteristics in literature. The identification of 222U was made based on observed Er-α, two- or three-signal correlated events using a fast data acquisition and combined analog and digital (CANDI) readout system. α total of 81 Er traces were recorded for 222U and analyzed with subsequent α decay chain: 222U -> 218Th -> 214Ra. FWHM≈40 keV for 8.7 MeV α particles, recorded as single events, ≈110 keV and ≈180 keV for multiple α events stored in a single trace with time differences of 1 μs and 0.17 μs, respectively. Deduced α-decay reduced widths, and neutron shell gap, the latter compared with FRDM95 and HFB26 theoretical calculations for Z=82-92,n=126 nuclei

Q-value: Estimated uncertainties (2012Wa38): 220 for Q(β-), 140 for S(n), 110 for S(p), 100 for Q(α)

Q-value: S(2n)=14850 140, S(2p)=5030 100, Q(εp)=-10 100 (2012Wa38); all values from systematic trend

Jπ(level) T1/2(level)
  0.0 0+ 4.7 µs 7 
% α ≈ 100

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Additional Level Data and Comments:

  0.00+ 4.7 µs 7 
% α ≈ 100
The radius parameter r0=1.529 fm 15 is deduced by assuming 100% α decay from ground state of 222U to ground state of 218Th, with HF=1.

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