1.   As the temperature rises, the copper atoms boil off into a chamber filled with helium gas.

2.   At room temperatures, copper atoms continually jiggle around, bouncing the tin atoms along the surface until they coalesced into larger clumps.

3.   Because tin atoms are larger than copper atoms, they cause a bulge when they enter the surface.

4.   Collisions with the helium atoms slow the copper atoms enough so that when two of them collide they stick together instead of bouncing apart.

5.   The collisions between protons and the nuclei of copper atoms produce sprays of new particles, some of which are antiprotons.