University of Wisconsin-Madison Physical Sciences Lab

The Askaryan Radio Array Drill Season 2013

Thursday, July 18th, 2013

For PSL engineers, designing equipment for use in extreme frigid temperatures involves meticulous consideration to the function and design of the equipment.  When the South Pole is the destination, other details become very complicated, for example the size when shipping. Everything that is sent to the Pole must be able to fit on a military cargo plane. Sending crates and boxes requires a lot of work, but items as large as the Askaryan Radio Array hose reel requires extensive planning and thought.

Instrument Technician Darrell Hamilton explained the complications involved with the ARA hose reel. Two additional size challenges were calculated when designing the reel: shipment and final assembly in the large equipment bay at the South Pole. Jeff Cherwinka was the lead engineer for the hose reel and he designed it with both space requirements in mind. For the reel to fit on the cargo plane it had to fold in on itself. Once it arrived at the South Pole, the hose reel had to undergo final assembly and be raised into an upright position. When raised into its upright position the hose reel now had to be able to pass through the bay door, however the reel gave a false appearance of not clearing the large maintenance bay door. Despite the team’s prior calculations on clearance, measurements were taken several times before the move took place. As Darrell said, “The clearance was minimal to come out of the building.”

Pretesting of the drill and hose reel took place close to the station before moving to remote areas and testing of the new drill went very well.  Darrell explains that the drill is a new technology that has not been used previously. He explains, “The method that was employed for dry hole drill was to have two hoses descend in tandem. One hose supplied the hot water for melting ice, while the second hose returned the melt water to the surface to be reheated and reused.”

Not only were the pretests successful, but the entire drilling season. Each of the holes were drilled to a depth of 200 meters and met all requirements. A total of thirteen holes were drilled at two stations located two kilometers apart, each station contains six holes that contain data acquisition electronics.

If future funding allows, the entire ARA project will contain 37 stations and will cover an area of 100 square kilometers, 100 times the size of the IceCube project.

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