Chemical Forums
Specialty Chemistry Forums => Nuclear Chemistry and Radiochemistry Forum => Topic started by: Dan1195 on August 28, 2007, 08:43:09 PM
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It appears the various labs have hit a brick wall with current technology when it comes to discovering hew elements. The reason is as follows
"Cold fusion" - Fusing two stable targets, one of them being Pb-208 or Bi-209. and the other being heaviest stable isotope of element needed to get the desired proton number i.e. Pb-208 + Zn-72 = Ds-269 + n. Beyond element 113 production cross sections likely become too low for observation during any reasonable amout of beam time.
"hot fusion" - Fusing Ca-48, desirable due to the very large n/p ratio for an practically stable isotope, with an ever heavier actinide. For Element 118 this means fusing iCa-48 with Californium. The problem is heavier elements cannot be used as targets due to short half-lives and inability to produce sufficient quantitied to use as targets. So the method used by Dubna is recent years in its current form is probably at an end.
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An experiment is under way at Dubna to try to make element 120 by bombarding Pu-244 with Fe-58. It will be very interesting to see if this works.
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It would be more interesting to see if it is confirmed!
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There is no way that you can win
And get sufficient Neutrons in!
Try neutron-starry coalescence
A Gamma -Bursting effervescence-
Kindly Nature might just do it.
But it seems She simply blew it!
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Getting enough neutrons to get to where the most stable nuclides are expected to be is a major drawback to the current techniques being used, besides the very small cross sections. Getting to where the most stable Superheavies are expected to be (e.g. Ds-290) with current methods is virtually impossible, even if radioactive beams with suitable intensity become available. Ideally you need a mechanism in between slow netron irradiation and uncontrolled fast neutrons, such as from a atomic weapon detonation. Unfortunately we know of no such method currently. Since they have no charge and free neutrons have short lifetimes, they can't be stored and used as projectiles. This is why we have very little data on neutron rich heavy elements.