Fission time measurements: a new probe into superheavy element stability.
نویسندگان
چکیده
Reaction mechanism analyses performed with a 4pi detector for the systems 208Pb + Ge, 238U + Ni and 238U + Ge, combined with analyses of the associated reaction time distributions, provide us with evidence for nuclei with Z=120 and 124 living longer than 10(-18) s and arising from highly excited compound nuclei. By contrast, the neutron deficient nuclei with Z=114 possibly formed in 208Pb + Ge reactions have shorter lifetimes, close to or below the sensitivity limit of the experiment.
منابع مشابه
Long - Range Fission Fragments from Radiogemc Lead ?
Fission tracks with a range 19% longer than tracks produced by uranium fission fragments were observed on mylar foils after a three year underground (100 m w. e.) exposure to 3600 cm2 of radlogemc lead. Ordinary lead which was simultaneously exposed to mylar foils under the same conditions yielded a background effect of only 3% of the effect from radiogenic lead. The observed long-range tracks ...
متن کاملNew features in the stability and fission decay of superheavy Thorium isotopes
Superheavy isotopes are highly neutron rich nuclei in the vicinity of neutron drip-line, stabilized by shell effect against the instability due to repulsive component of nuclear force, analogous to superheavy elements similarly stabilized against Coulomb instability. Here we discuss the stability and fission decay properties of such nuclei in the Th region and show that they are stable against ...
متن کاملExploring the island of superheavy elements
Over the last thirty years, experimentalists have, so to speak, launched an expedition to explore the predicted “island of superheavy elements”—a region of increasingly stable nuclei around atomic number 114 (Fig. 1). So far they have reported, on average, the discovery of one new element every two and a half years. Now, a Russian-American collaboration headed by Yuri Oganessian at the Joint In...
متن کاملDissipation-fluctuation dynamics of fusion-fission reactions and synthesis of superheavy elements
Dynamical treatments of fission processes are briefly reviewed with an emphasis on the strong dissipation or friction for collective motions of nuclei in high excitation. The theories are applied to synthesis of superheavy elements. Characteristic features of formation and surviving are discussed with reference to possible incident channels. Theoretical prediction are presented on favorable inc...
متن کاملEnhanced stability of superheavy nuclei due to high-spin isomerism.
Configuration-constrained calculations of potential-energy surfaces in even-even superheavy nuclei reveal systematically the existence at low excitation energies of multiquasiparticle states with deformed axially symmetric shapes and large angular momenta. These results indicate the prevalence of long-lived, multiquasiparticle isomers. In a quantal system, the ground state is usually more stabl...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 101 7 شماره
صفحات -
تاریخ انتشار 2008