Based on the cold fusion reaction valleys, referring to the minima in the p
otential energy surfaces calculated on quantum mechanical fragmentation the
ory, some of us and collaborators suggested the use of a Kr-86 beam or its
neighbouring nuclei in their very first publications of 1976-7. More recent
ly, one of us (RKG) and collaborators stressed its use again in 1993-4. In
view of the very recent experiments, reporting the use of a Kr-86 beam for
the cold synthesis of the Z = 118 element, here we have re-investigated thi
s problem for a large number of Z = 104-120 nuclei. We find that the use of
a Kr-86 beam for cold fusion reactions is as appropriate as the Pb and Ca
nuclei and the optimum targets are Yb-174, W-184 and Pb-208, respectively,
for synthesizing the:(260)(106)Sg, (270)110 and (294)118 nuclei. The Kr-86
+ Pb-208 is the reaction used in the above-mentioned Berkeley and GSI exper
iments. For other elements, lighter than Z = 118, the Se-34 beam is found t
o compete with the Kr-36 beam, whereas for Z > 118 elements Sr-38 is shown
to be a natural choice, Ge-32 and Zr-40 are found to be more suitable for t
he production of neutron-rich isotopes, thereby requiring the use of radioa
ctive nuclear beams. The radioactive nuclear beams (and targets) are predic
ted to be of great use for many other nuclei. The role of Kr-86 (being simi
lar to the doubly magic Pb-208 Or Ca-48) is perhaps related to the recently
predicted strong shell stabilizing effects of Kr-76 in cluster decay studi
es.