Friday, October 29, 2010

The Coming Antarctic Season

Preparation for the coming Antarctic field season are in full swing, in both IceCube and ARIANNA.

On ARIANNA, Steve Barwick and Jordan Hanson visited LBNL last week, to learn about the station hardware and software. They will be going out to Moore's Bay in early December, to recondition the station, and perform a number of calibration measurements. These calibrations should allow us to set a limit on the flux of ultra-high energy neutrinos. Although the limit from one station will not be very stringent, carrying out the analysis through to the end is a good way to convince ourselves (and peer reviewers) that we understand the system thoroughly.

Unfortunately, even though the sun is now above the horizon 24 hours/day, the station has not yet 'woken up' from the Antarctic winter hiatus. The most likely possibility (also the most optimistic) is that the battery cracked during the winter. There are some good reasons to believe this - the charge controller left it in a discharged state, and batteries are known to be a problem at low temperatures. Alternately, maybe the solar panels are still coated with snow, or, more likely, the Iridium antenna or some other part broke. The worst case scenario would be if the station failed mechanically, and that the solar panels, etc. will be strewn across the Ice Shelf, buried under a winters accumulation of snow.

The first IceCube personnel are already in New Zealand, waiting for flights to McMurdo station. The plan for IceCube is to drill the final seven holes and deploy strings in them, and then prepare the drilling system for hibernation. In addition, two of the strings will include sodium-iodide crystals which will be used to look for dark matter. Although the IceCube project included funding to disassemble the drilling system and move it North (to avoid leaving any junk in Antarctica), the drill has many future applications. In particular, if the dark matter prototype works well, then additional crystals may be deployed, in special background-free pressure vessels.

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