Liquid helium leaks in the world's largest particle accelerator were probably caused by a problem with a flexible hose in the liquid helium transport circuits, the organization said an article in its official bulletin, published last week.
The hose vented helium into the vacuum insulation of the Large Hadron Collider (LHC), Cern officials suspect.
Cern has revised the restart date of the LHC several times since the experiment was put out of action last September by an electrical fault. According to the latest estimates, the particle acceleration experiment is unlikely to restart before mid-November.
The vacuum leaks occurred in sectors 8-1 and 2-3 in July. At the time, Cern said that the sectors would have to be warmed from 80K to room temperature to effect repairs.
On Monday, the organization changed that plan, saying the vacuum subsectors at the end of the sectors will be warmed to room temperature to locate the leaks and repair them. The rest of those sectors will "float" in temperature from 80K.
Both leaks happened at the place where the final magnet of those sectors, which is known as Q7, joins the electrical feedbox, known as the DFBA.
The LHC experiment is designed to enable research into fundamental questions about nuclear particles, such as the existence of dark matter.