[gippgig]

A recent paper (The European Physical Journal A, published online July 25 ("DOI 10.1140/epja/i2008-10607-5")) examines the decay of superheavy nuclides and finds that there is no shell closure at Z=114. This paper suggests that the shell closure is around Z=122, that elements 112-118 have deformed (flattened) rather than spherical nuclei, and that the production cross-section will decline precipitously around Z=119.
If the closed shell is at 122 then ³⁵⁰122 looks very interesting. This should be a doubly magic nuclide slightly on the neutron rich side of the optimum proton/neutron ratio, the ideal situation for maximum lifetime. Unfortunately I do not think there is currently any even remotely plausible way to make it.

[Dan1195]

The predicted cross-section decline is interesting, as this would at least partly explain why the first attempt at element 120 (by Dubna I believe) was unsuccessful. The loss of the use of ⁴⁸Ca as a projectle may also be a factor.

The problems creating neutron rich very heavy elements are well known. The n/p ratio increases for heavier nuclei which means the product of two fused nuclei will always be neutron deficient. At some point the practicality of "hot" fusion reactions to create SHE's will end due to declining lifetimes due to neutron defiency and falling cross-sections, even with RIB's.

To get isotopes like you mention would require some form of breakthrough in nuclear physics. I guess if you somehow force a very large number of nucleons into a very confined area and get them to perform a fusion-fission reation. Of course the problem is the coloumb barrier. Some group in the Ukraine has claimed to do something like this via some kind of electon beams which causes a collapse of nuclei into each other overcoming the barrier. But since they tend to show up at cold fusion conferences, do not produce peer reviewed work, have yet to ask respected international labs to examine their samples and wont tell anyone exactly how they did it (they want to "patent" their technique, which runs contrary to how basic science research works), this claim has was much validity as the Marinarov element 122 claim.