Work Permit 0209    Approved
Date of Request Requestor Job Type
Tue Jan 07, 2014 James Kilmer
Detector Maintenance
Work Start Date Work Duration Number of People
Wed Jan 08, 2014 more than 2 weeks 3 people
Work Location Detector or System Special Tools
Shaft, Tunnel and Hall Cranes both Cranes
Detailed Description
This task is to fill the Minerva helium target with liquid helium. We need to remnove all of the roof sections over the Minerva detector, The target is cooled down to ~ 100K with liquid nitrogen from 160 liter dewars. Once ther target vessel has some liquid nitrogen in it all of the nitrogen is removed. The vessel is purged to helium. Once the vessel is purged the vessel is filled with liquid helium and the small refrigerator is started up. Cleanup includes storing all of the filling equipment and putting the roof back on over the detector. The task requires both shaft and cavern cranes. The dewars are lowered into the tunnel with the shaft crane using a safety approved procedure.
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Last updated: Thu Sep 25, 2014 17:38:34 EDT