The last few days have been quite challenging. Not only are we dealing with the specter of significant budget cuts, but last Thursday a fire in the access shaft at Soudan stopped all operations there, and here at the lab Sunday’s violent lightning storm brought a lot of equipment down, causing the Tevatron to quench and damaging one of its dipoles. With these problems for the MINOS and CDMS detectors at Soudan, and the Tevatron here, our resiliency is being put to the test.
Fortunately the fire in the access shaft at Soudan has been controlled; emergency personnel have been down to the bottom level of the mine and re-established communications. No one was in the mine at the time of the fire. The hoist is operating, and we expect access to the laboratory in the next couple of days. At this point we do not expect damage to MINOS and we hope for either no damage or minimal damage to CDMS due to the uncontrolled warm-up of the cryogenics system. The emergency response of the Minnesota Department of Natural Resources (DNR) that operates the mine and the University of Minnesota that leases the underground laboratory has been impressive. We also received offers of assistance from other laboratories and agencies for which we are very appreciative. Updates to the situation in Soudan can be found on our website. We will now focus on reestablishing operations in the mine and the detectors. We will not have a schedule for reestablishing full operations until the DNR assesses the required repairs to continue to operate the mine safely.
The repair of the Tevatron is more predictable. Up to now, the Tevatron operation has been truly impressive, with more than 1.2 inverse femtobarns accumulated so far this fiscal year. Although we have replaced damaged magnets before, we have only interrupted operations three times in the past five years for unexpected component replacements. Over the history of the Tevatron’s Run 2 we have changed two dozen cryogenic devices. The particular magnet that was damaged on Sunday will take approximately two weeks to replace, and we expect to be back in full operation early in April to continue the last extraordinary run of the Tevatron.
The ability to recover quickly from unexpected events such as we experienced last week depends on careful planning for such contingencies. Events such as these also give us the opportunity for lessons learned that will make future operations more resilient and safe.