ADOPTED LEVELS for 208Th

Authors: Balraj Singh and Michael Birch |  Citation: ENSDF |  Cutoff date: 15-MAY-2011 

Author: M. J. Martin |  Citation: Nucl. Data Sheets 108,1583 (2007) |  Cutoff date: 1-Jun-2007 

 Full ENSDF file | Adopted Levels (PDF version) 


S(p)= 1.76×103 keV 6Q(α)= 8.20×103 keV 3
Reference: 2012WA38

General Comments:

2006Ku07: 9Be(238U,X), E=1 GeV/nucleon. Fragmentation products were identified by combining time-of-flight, position, and energy-loss information. Indications were found for the occurrence of a few events at the position corresponding to 208Th; however, the statistics and the resolution of the ion identification procedure at this position were not sufficient to claim unambiguous observation of this isotope. An upper limit for the production of 208Th was set at <0.67 nb 14. Experiments at GSI facility

2010He25: 208Th nuclide identified in 147Sm(64Ni,3n) complete fusion reaction with beam energies 288 MeV and 294 MeV produced by the UNILAC of the GSI facility. Target consisted of 327-546 μg/cm2 thick 147SmF3 enriched to 96.4% purity evaporated onto a 40 μg/cm2 carbon foil and covered with a 10 μg/cm2 carbon layer. Evaporation residues were velocity filtered by SHIP and implanted into a 300 μm thick, 35x80 mm2 16-strip positron-sensitive silicon detector (PSSD) mounted at the focal plane of SHIP, each with an energy resolution of about 25 keV (FWHM). Six silicon box detectors were mounted in an open box geometry upstream from the PSSD to measure the energy of α particles which escaped from the PSSD in the backward direction. The sum of the energy depositions in both the PSSD and box detectors gave the full energy of the escaping α-particle, though at a lower energy resolution than the PSSD alone. Three time-of-flight (tof) detectors in front of the box+PSSD system were used to distinguish reaction products from scattered beam particles, transfer reaction products and scattered target-like nuclei. Identification based on the observation of energy, position and time correlated α-decay chains. α fourfold segmented Clover Ge detector was also installed for α-γ or α(x ray) coincidence measurements with ΔT(α-γ)|<5 μs, however no coincidences were seen.

2008Sc02: calculated Fermi level and proton separation energy using the spherical Hartree-Fock-Bogoliubov mean-field theory with a finite-range force supplemented by continuum and particle-number projection effects.

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

Q-value: S(n) from 1997Mo25, S(p) from 2011AuZZ, Q(α) deduced from measured Eα=8044 30 (2010He25) based on two events where the entire energy deposition occurred in the pssd.

Q-value: Q(εp)=5860 60, S(2p)=1460 40 (2011AuZZ). S(2n)=19730 (1997Mo25,calculated),





E(level)
(keV)
Jπ(level) T1/2(level)
  0 0+ 1.7 ms +17-6 
% α ≈ 100

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
  00+ 1.7 ms +17-6 
% α ≈ 100
Production σ=95 pb +219-79 for E(64Ni)=294 MeV for one event; σ=22 pb +20-13 for E(64Ni)=288 MeV for three events (2010He25).
E(level): Production σ=95 pb +219-79 for E(64Ni)=294 MeV for one event; σ=22 pb +20-13 for E(64Ni)=288 MeV for three events (2010He25).

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