Underground research to solve matter-antimatter mystery

Scientists are building a 40 kg germanium detector, 4,850 feet beneath the earth's surface in a laboratory in the US, to help explain the puzzling imbalance between matter and antimatter generated by the Big Bang.
The US Department of Energy's Oak Ridge National Laboratory (ORNL) has begun delivery of germanium-76 detectors to the underground laboratory in South Dakota with the intention of building the germanium detector, capable of detecting the theorised neutrinoless double beta decay.
The detection might help to explain the matter-antimatter imbalance.
"It might explain why we're here at all. It could help explain why the matter that we are made of exists," said David Radford, who oversees specific ORNL activities in the Majorana Demonstrator research effort.

Radford, a researcher in ORNL's Physics Division and an expert in germanium detectors, has been delivering germanium-76 to Sanford Underground Research Laboratory (SURF) in Lead, South Dakota, for the project.
After navigating a Valentine's Day blizzard on the first two-day drive from Oak Ridge, Radford made a second delivery in March.

Before the detection of the unobserved decay can begin, however, the germanium must first be processed, refined and enriched.
The 42.5 kg of 86 per cent enriched white germanium oxide powder required for the project is valued at USD 4 million and was transported from a Russian enrichment facility to a secure underground ORNL facility in a specially designed container.

The container's special shielding and underground storage limited exposure of the germanium to cosmic rays.
Without such preventative measures, Radford said, "Cosmic rays transmute germanium atoms into long-lived radioactive atoms, at the rate of about two atoms per day per kilogramme of germanium.
"Even those two atoms a day will add to the background in our experiment. So we use underground storage to reduce the exposure to cosmic rays by a factor of 100," Radford said.
The germanium must further undergo a reduction and purification process at two Oak Ridge companies, Electrochemical Systems, Inc (ESI) and Advanced Measurement Technology (AMETEK), before being moved to its final destination in South Dakota.

To date, ORNL has delivered - via Radford's two trips - nine of the enriched detectors, which are valued at about USD 2 million including the original cost of the enriched germanium oxide powder.
Requiring a total of 30 enriched detectors, the Majorana Demonstrator is not expected to be fully complete and operational until 2015.
ORNL serves as the lead laboratory for the Majorana Demonstrator research effort, a collaboration of research institutions representing the United States, Russia, Japan and Canada.