was published in Physical Review C in 2008. A rebuttal by the Marinov group was published in Physical Review C after the published comment. A repeat of the thorium experiment using the superior method of accelerator mass spectrometry (AMS) failed to confirm the results, despite a 100-fold better sensitivity. This result throws considerable doubt on the results of the Marinov collaboration with regards to their claims of long-lived isotopes of thorium, roentgenium, and unbibium. Current understanding of superheavy elements indicates that it is very unlikely for any traces of unbibium to persist in natural thorium samples. Naming Using Mendeleev's nomenclature for unnamed and undiscovered elements, unbibium should instead be known as eka-thorium. After the recommendations of the IUPAC in 1979, the element has since been largely referred to as unbibium with the atomic symbol of (Ubb), as its temporary name until the element is officially discovered and synthesized, and a permanent name is decided on. Scientists largely ignore this naming convention, and instead simply refer to unbibium as "element 122" with the symbol of (122), or sometimes even E122 or 122. Prospects for future synthesis Every element from mendelevium onward was produced in fusion-evaporation reactions, culminating in the discovery of the heaviest known element oganesson in 2002 and most recently tennessine in 2010. These reactions approached the limit of current technology; for example, the synthesis of tennessine required 22 milligrams of 249Bk and an intense 48Ca beam for six months. The intensity of beams in superheavy element research cannot exceed 1012 projectiles per second without damaging the target and detector, and producing larger quantities of increasingly rare and unstable actinide targets is impractical. Consequently, future experiments must be done at facilities such as the superheavy element factory (SHE-factory) at the Joint Institute for Nuclear Research (JINR) or RIKEN, which will allow experiments to run for longer stretches of time with increased detection capabilities and enable otherwise inaccessible reactions. It is possible that fusion-evaporation reactions will not be suitable for the discovery of unbibium or heavier elements. Various models predict increasingly short alpha and spontaneous fission half-lives for isotopes with Z = 122 and N ~ 180 on the order of microseconds or less, rendering detection nearly impossible with current equipment. The increasing dominance of spontaneous fission also may sever possible ties to known nuclei of livermorium or oganesson and make identification and confirmation more difficult; a similar problem occurred in