Scientists working on the 4850 Level, at the temporary laboratory for the Majorana Demonstrator project, started electroplating the world's purest copper on July 20. But don't look for dramatic results yet. "Electroplating is even less exciting than growing grass," Sanford Lab Science Liaison Director Jaret Heise says.
The process is simple but slow. Copper nuggets are added to the outer rings in each of 10 electroforming "baths," which also are filled with a sulfuric acid solution. A stainless steel cylinder, called a "mandrel," is lowered into the center of each bath. Each mandrel is in the shape of a part needed to build the experiment. When an electrical current is added, the mandrel becomes a cathode, upon which a thin layer of copper begins for form—at a rate of about 70 millionths of a meter per day. In comparison, grass grows at a blistering 12.7 millimeters per day, or about 180 times faster.
No worries. The Majorana Collaboration is patient. In five months, voila! About half an inch of copper will have been formed on the mandrel, with virtually none of the routine impurities that result on the surface when cosmic radiation hits copper.
The temporary cleanroom will operate for about two years to make the ultra-pure, radiation-free copper needed to build the Majorana Demonstrator experiment.
The 10 electroforming baths can hold 15,000 pounds of copper at a time.
Majorana will look for evidence of a rare phenomenon called "neutrinoless double-beta decay," which could help answer question, Why did matter win its cosmic battle with anti-matter?