|the isotope needed would only be in concentrations of less than 1 percent|
How do you get neutrons? Usually this is done with radioactive sources ( as far as I know). There may be a couple other ways. The first way is by making a Polywell device and fusing deuterium. This will produce your neutrons all right, but you may want to slow them down. Also, you don't know if this is going to produce the number you need in order to make it worthwhile.
Another way is by way of LENR. Widom Larsen proposes that a suitable hydride can make ultra low momentum neutrons. These neutrons, assuming that they exist, can be used to bombard the mercury and make gold.
|mercury to gold? you gotta be kiddin' me|
This is a bit whimsical because- once you make the gold, and assuming that you can make a lot of it at a relatively cheap price ( quite a presumption by the way), you will have destroyed its economic basis. Sort of self defeating. But diamonds can be made artificially. If there was no way to tell them from the real ones, diamonds would be worthless. ( ha ha)