4,688 research outputs found
Discovery of Long-Lived Shape Isomeric States which Decay by Strongly Retarded High-Energy Particle Radioactivity
The reaction 28Si + 181Ta has been studied at E(Lab) = 125 and 135 MeV.
Coincidences between high energy particles and various X- and gamma-rays from
abnormally long-lived states were observed. e.g. 7.8 - 8.6 MeV alpha-particles
with gamma-rays of a superdeformed band, 5.1 - 5.5 MeV alpha-particles with X-
and gamma-rays of W, Re, and Pt, and 3.88 MeV particles (interpreted as
protons) with 185.8 keV gamma-rays. The data are interpreted in terms of the
production of long-lived (t(1/2) of several months) high spin isomeric states
in the second well of the potential in the parent nuclei, which decay to the
normal states in the daughters, and in the third well of the potential, which
decay to the second well.Comment: 25 pages including 11 figures and 3 table
Strongly Enhanced Low Energy Alpha-Particle Decay in Heavy Actinide Nuclei and Long-Lived Superdeformed and Hyperdeformed Isomeric States
Relatively low energy and very enhanced alpha-particle groups have been
observed in various actinide fractions produced via secondary reactions in a
CERN W target which had been irradiated with 24-GeV protons. In particular,
5.14, 5.27 and 5.53 MeV alpha-particle groups with corresponding half-lives of
3.8(+ -)1.0 y, 625(+ -)84 d and 26(+ -)7 d, have been seen in Bk, Es and Lr-No
sources, respectively. The measured energies are a few MeV lower than the known
g.s. to g.s. alpha-decays in the corresponding neutron-deficient actinide
nuclei. The half-lives are 4 to 7 orders of magnitude shorter than expected
from the systematics of alpha-particle decay in this region of nuclei. The
deduced evaporation residue cross sections are in the mb region, about 4 orders
of magnitude higher than expected. A consistent interpretation of the data is
given in terms of production of long-lived isomeric states in the second and
third wells of the potential-energy surfaces of the parent nuclei, which decay
to the corresponding wells in the daughters. The possibility that the isomeric
states in the third minimum are actually the true or very near the true ground
states of the nuclei, and consequences regarding the production of the
long-lived superheavy elements, are discussed.Comment: 27 pages including 8 figures and 4 table
Coherent Description for Hitherto Unexplained Radioactivities by Super- and Hyperdeformed Isomeric States
Recently long-lived high spin super- and hyperdeformed isomeric states with
unusual radioactive decay properties have been discovered. Based on these newly
observed modes of radioactive decay, consistent interpretations are suggested
for previously unexplained phenomena seen in nature. These are the Po halos,
the low-energy enhanced 4.5 MeV alpha-particle group proposed to be due to an
isotope of a superheavy element with Z = 108, and the giant halos.Comment: 8 pages, 2 figures, 1 table, to be published in Int. J. Mod. Phys.
INTERCELLULAR CONTACTS BETWEEN SMOOTH MUSCLE CELLS IN THE NEOINTIMA OF THE AUTOGENOUS REVERSED SAPHENOUS VEIN GRAFTS
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Super- and Hyperdeformed Isomeric States and Long-Lived Superheavy Elements
The recent discoveries of the long-lived high spin super- and hyperdeformed
isomeric states and their unusual radioactive decay properties are described.
Based on their existence a consistent interpretation is given to the production
of the long-lived superheavy element with Z = 112, via secondary reactions in
CERN W targets, and to the low energy and very enhanced alpha-particle groups
seen in various actinide fractions separated from the same W target. In
addition, consistent interpretations are suggested for previously unexplained
phenomena seen in nature. These are the Po halos, the low-energy enhanced 4.5
MeV alpha-particle group proposed to be due to an isotope of a superheavy
element with Z = 108, and the giant halos.Comment: 4 pages. Contribution to the 2nd Int. Conf. on the Chemistry and
Physics of the Transactinide Elements (TAN 03) Napa California, November 200
New Outlook on the Possible Existence of Superheavy Elements in Nature
A consistent interpretation is given to some previously unexplained phenomena
seen in nature in terms of the recently discovered long-lived high spin super-
and hyper-deformed isomeric states. The Po halos seen in mica are interpreted
as due to the existence of such isomeric states in corresponding Po or nearby
nuclei which eventually decay by gamma- or beta-decay to the ground states of
210Po, 214Po and 218Po nuclei. The low-energy 4.5 MeV alpha-particle group
observed in several minerals is interpreted as due to a very enhanced alpha
transition from the third minimum of the potential-energy surface in a
superheavy nucleus with atomic number Z=108 (Hs) and atomic mass number around
271 to the corresponding minimum in the daughter.Comment: 8 pages, 8 figures, 5 tables. Paper presented at VII Int.
School-Seminar on Heavy Ion Physics, May 27 - June 1, 2002, Dubna, Russi
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