Scientists are still searching for the island of stability when it comes to synthesis of new super heavy elements.  My general understanding is that they “shoot” streams of a lighter element at a heavy element target.  I think to create element 117, they used Ca-48 and an isotope of Bk.  I expect that given shorter half lives for elements beyond Bk, it might not be feasible to use a heavier target, but what about heavier elements from the other side, such as Cu or Fe instead of Ca?  Couldn’t there be some combination that could get to the magic number of protons and neutrons, or is current equipment incapable of utilizing those elements for some reason?

Heavier elements as the projectile probably can't be accelerated to the necessary speed, and require a higher energy to overcome the Coulomb barrier.

E = kq₁q₂/r    q is proportional to the atomic number, Z

Let's say you want to get to Z=120, and no protons are lost from the collision (or want a smaller Z but protons are lost)

If you use Z = 20 and 100, the product is 2000. If you use 60 and 60, the product is 3600. IOW, you need 80% more energy to overcome the barrier.

 

8 minutes ago, swansont said:

Heavier elements as the projectile probably can't be accelerated to the necessary speed, and require a higher energy to overcome the Coulomb barrier.

E = kq₁q₂/r    q is proportional to the atomic number, Z

Let's say you want to get to Z=120, and no protons are lost from the collision (or want a smaller Z but protons are lost)

If you use Z = 20 and 100, the product is 2000. If you use 60 and 60, the product is 3600. IOW, you need 80% more energy to overcome the barrier. Also since a lighter target will end up with more KE as the projectile approaches, you need even more energy for the projectile.

 

 

Interesting.  So then it would seem that the issue is their particle accelerators are unable to impart sufficiently high energy to run the experiment with the more closely weighted particles?