ADOPTED LEVELS for 179Tl
Author: Coral M. Baglin | Citation: Nucl. Data Sheets 110, 265 (2009) | Cutoff date: 15-Nov-2008
Full ENSDF file | Adopted Levels (PDF version)
Q(β-)=-1.033×104 keV 9 | S(n)= 1.156×104 keV SY | S(p)= -7.5×102 keV 5 | Q(α)= 6710 keV 5 | ||
Reference: 2012WA38 |
E(level) (keV) | Jπ(level) | T1/2(level) |
0.0 | (1/2+) | 0.23 s 4 % α < 100 % ε = ? % p = ? |
0.0+X | (11/2-) | 1.5 ms 3 % α ≤ 100 % IT = ? % ε = ? % p = ? |
Additional Level Data and Comments:
E(level) | Jπ(level) | T1/2(level) | Comments |
0.0+X | (11/2-) | 1.5 ms 3 % α ≤ 100 % IT = ? % ε = ? % p = ? | Jπ(level): 187Tl, 185Tl, 183Tl have isomeric h9/2 states at 336, 454, 625, respectively, which deexcite via E3 transitions to a d3/2 level at E=250-300 keV. These energy systematics suggest that the corresponding states in 181Tl and 179Tl may occur near 850 and 1100 keV; from the E3 transition energy and T1/2 systematics, 1998To14 predict a T1/2 value for E3 deexcitation which is close to the level T1/2 observed for 181Tl but very much lower than T1/2=1.5 ms adopted for the 0.0+x level of 179Tl. 1998To14 suggest, therefore, that the h11/2 orbital may lie below the h9/2 orbital in 179Tl, allowing α decay to compete successfully with M4 γ deexcitation. Note that 177Tl has an isomeric (11/2-) level at E=807 18 (1999Po09). |
α decay from 179Tl:
α 6569 10 α from 179Tl(g.s.), and 7096 10 and 7213 10 α’s from a 0.0+x level are observed, and all are correlated with a 6435α from 175Au (1998To14). Thus, α’s from the 0.0+x level feed 175Au levels separated by 120 14 keV. Further, 1998To14 suggest that, unless the 6435α from 175Au is a doublet, the 6569α and 7213α feed either the same level in 175Au or levels connected by a prompt γ. However, from systematics, both 1/2+ and 11/2- isomeric states should exist in 175Au, and 2002Ro17 report both a 6438α and a 6412α from 175Au. Therefore, it seems probable that the 6435α of 1998To14 is indeed a doublet. Correlation data from 2002Ro17 imply that the stronger α from 179Tl(0+x) (i.e., the 7213α) feeds 175Au(11/2-) and the 6569α from 179Tl(g.s.) feeds 175Au(1/2+). If the 6569α is a g.s. to g.s. transition, then x |>659 keV for the 0.0+x level of 179Tl.
Q-value: Note: Current evaluation has used the following Q record -10.300 syst 11.62×103SY -730 506718 8 2003Au03
Q-value: Uncertainty is 200 keV and 120 keV in Q(β-) and S(n), respectively (2003Au03).