0000000000624710
AUTHOR
Glenn T. Seaborg
showing 3 related works from this author
Criteria for the Discovery of Chemical Elements
1976
The availability of suitable heavy-ion accelerators should make it possible to synthesize and identify additional heavy transuranium elements. Criteria for adequate proof that a new element has been synthesized or found in nature and identified are suggested. The basic criterion must be the proof that the atomic number of the new element is different from the atomic numbers of all previously known elements. Chemical identification constitutes an ideal proof; the procedure must be valid for application to individual atoms in an unequivocal manner. Also satisfactory is the identification of characteristic x rays in connection with the decay of the isotope of the new element. This is likely to…
Excitation functions for production of heavy actinides from interactions ofCa40andCa48ions withCm248
1985
Excitation functions have been measured for production of isotopes of Bk through Fm in bombardments of /sup 248/Cm with 234- to 294-MeV /sup 40/Ca ions and with 239- to 318-MeV /sup 48/Ca ions. The maxima of the isotopic distributions for these elements occur at only 2 to 3 mass numbers larger for /sup 48/Ca than for /sup 40/Ca reactions. The shapes of the distributions and the half-widths of about 2.5 mass numbers are quite similar to those observed previously for reactions of /sup 16/O, /sup 18/O, /sup 20/Ne, and /sup 22/Ne with /sup 248/Cm. In general, the excitation functions for /sup 40/Ca show maxima near the Coulomb barrier while those for /sup 48/Ca are about 20 MeV above the barrie…
Attempts to Produce Superheavy Elements by Fusion ofCa48withCm248in the Bombarding Energy Range of 4.5-5.2 MeV/u
1985
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 ${10}^{\ensuremath{-}35}$ ${\mathrm{cm}}^{2}$.