Dark matter hunt to go deeper

LONDON - Scientists are considering relocating an underground experiment searching for dark matter to an even deeper site.

Cosmic rays striking the Earth could completely mask the rare dark matter events sought by the experiment.

Team members want to cut out as much of this cosmic ray interference as possible, even if it means moving the experiment 2km below ground.

This could help them positively identify the particles thought to make up dark matter.

Dr Marek Kos, who is a team member on the Cryogenic Dark Matter Search II (CDMSII) project, said the experiment could be relocated from a mine in Minnesota to a deeper facility in Ontario, Canada.

CDMSII operates at extremely low temperatures and detects the energy released when particles hit atoms in germanium and silicon crystals within the detectors.

“If we have another successful run at Soudan, we’re planning to go even deeper, possibly - to the SNOLAB in Sudbury, Ontario, in Canada,” the BBC News quoted Dr Kos as saying.

“It is at 6,000m water equivalent - a figure that’s used to compare it to other experiments - but it’s about 2km underground,” said Kos.

Going this deep would help reduce the background signals from cosmic ray muon particles. Moving deeper underground can only reduce this effect.

“We were critical of those events when we saw them. Discovering WIMPs is a big deal and you’ve got to be sure you’re looking at the right thing,” said Kos.

Scientists are in the process of installing improved detection equipment at the Soudan mine.

“We’re fabricating bigger detectors and some of those are already underground and operational,” said Kos.

Kos of Syracuse University presented the findings at the International Conference on High Energy Physics (ICHEP) in Paris. (ANI)