SPARO at South Pole

SPARO and the first team from Northwestern arrived at Pole on December 10th. Liquid Helium arrived at Pole on January 10. SPARO was operated on Viper during Jan. 20th - Jan. 26th. We carried out a host of tests and measurements, incuding instrument noise, synchronous offsets, software interface, and pointing/focus.

The weather conditions during these six days were quite bad: a four-day blizzard followed by two days of exceptionally high submillimeter opacity. So we carried out the pointing and focus tests using a liquid-nitrogen cooled "compact source" placed on the roof of a building located 1000 feet from the telescope. Everything checked out nicely.

After removing SPARO, the upgraded Corona instrument was successfully tested on Viper during the last three weeks of the season. Meanwhile, we warmed SPARO so that Greg and John could subsequently cool it down by themselves as practice. The cooldown went well, and the winter-overs have now also done three Helium-3 cycles and numerous He-4 fills on their own.

We decided on a conservative schedule for the winter: start with the proven instrument (Corona) and install the new one (SPARO) only after a few months of successful operation of Corona. In order to conserve liqiuid Helium, SPARO was warmed up in mid-February. If all goes well, we'll begin making the first large-scale map of the magnetic field in our Galaxy's nucleus in July!