0000000000732763
AUTHOR
C. Frink
Fast volatilization of some lanthanide and actinide elements from titanium surfaces
The ad- and desorption of trace quantities of the lanthanide elements lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, and ytterbium and of the actinide elements americium and curium were investigated by thermochromatographic and isothermal measurements with hot titanium columns. The adsorption enthalpies deduced from the experimental data are in reasonable agreement with calculated values which indicate considerable variations in volatility under such conditions. More volatile elements can quickly be separated from less volatile elements by heating the mixture on titanium in high vacuum.
Reactions of40Ar with233U,235U, and238U at the barrier
Production cross sections for target-like transfer products in reactions of40Ar with233,235,238U at the barrier were determined using radiochemical techniques. The heaviest products detected are isotopes of californium (Z=98). In addition to the quasi-elastic component of the isotopic distributions observed in the vicinity of uranium, there are also relaxed contributions throughout the entire region. The peak positions of the isotope distributions of this component for fixed atomic number, after the transfer of > 3 charges, approach closely the minimum of the potential energy surfaces (PES). The experimental results thus indicate the cold formation of the reaction products. A search for lon…
Attempts to Produce Superheavy Elements by Fusion ofCa48withCm248in the Bombarding Energy Range of 4.5-5.2 MeV/u
A search for superheavy elements was made in bombardments of $^{248}\mathrm{Cm}$ with $^{48}\mathrm{Ca}$ ions performed at projectile energies close to the interaction barrier in order to keep the excitation energy of the compound nucleus $Z=116$, $A=296$ as low as possible. No evidence for superheavy nuclei was obtained in a half-life region from 1 \ensuremath{\mu}s to 10 yr with a production cross section greater than ${10}^{\ensuremath{-}34}$ to ${10}^{\ensuremath{-}35}$ ${\mathrm{cm}}^{2}$.