Detailed spectroscopy of 195Bi
Herzan, A., Juutinen, S., Auranen, K., Grahn, T., Greenlees, P., Hauschild, K., . . . Uusitalo, J. (2017). Detailed spectroscopy of 195Bi. Physical Review C, 96 (1), 014301. doi:10.1103/PhysRevC.96.014301
Published in
Physical Review CAuthors
Date
2017Copyright
©2017 American Physical Society
An experiment focused on the study of shape coexistence and new high-spin structures in
195
Bi
has been performed. The nucleus is in a transitional region of the bismuth isotope chain. A large number of new states have been found, resulting in a significant extension of the previously known level scheme. Several new collective structures have been identified. A strongly coupled rotational band built upon the
13
/
2
+
isomeric state was extended up to
I
π
=
(
49
/
2
+
)
and an energy of 5706 keV. The
I
π
=
31
/
2
+
member of the
π
i
13
/
2
band was also found to feed a new long-lived isomeric state with an excitation energy of 2616 keV and a spin and parity of
I
π
=
29
/
2
+
. The half-life of the
29
/
2
+
isomeric state was determined to be
1.49
(
1
)
μ
s
. It decays via the emission of 457-keV
E
2
and 236-keV
E
1
transitions, respectively. A low-energy 46-keV
E
2
transition has been identified to depopulate the (
29
/
2
−
) isomeric state, with a measured half-life of
T
1
/
2
=
614
(
5
)
ns
. This transition allows the excitation energy of the isomeric state to be determined as 2381 keV. The feeding patterns of both
29
/
2
+
and (
29
/
2
−
) isomeric states have also been described. This is the first time collective structures have also been observed up to high spins and excitation energies in the neutron-deficient
195
Bi
nucleus. Evidence for the manifestation of shape coexistence in
195
Bi
is also discussed.
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