A poor soldering job was the most likely cause of the failure that derailed the world's largest atom collider last month, a senior Cern scientist has said.
Lyn Evans, project leader of the Large Hadron Collider at the European Nuclear Research Organization (Cern) outside Geneva, said the source problem was small.
"It happens quite often in electrical connections," Evans said, adding that he thought the fault resulted from human error on one electrical connection – one of 10,000 inside the machine.
The fault halted operations for at least two months, which meant that the collider would not be restarted until spring, after the obligatory shutdown for the winter because electricity prices are too costly.
Evans says he has not been able to examine the damage because the collider is still too cold to be opened up.
The damaged section of the collider has to be warmed gradually to room temperature over five weeks so that humans can work inside and make repairs. Then it will take another five weeks to be chilled again.
Before the failure, the plan had been to step up power on the collider so that scientists could start with test collisions of subatomic particles before the winter shutdown. That will have to wait until next April.