Week One

Saturday, December 6, 2014

I have now officially completed my first full work week here at Pole. (The schedule is six days on, one day off – most people work 8:30am to 5pm Monday through Saturday.) My typical weekday starts with a group meeting over breakfast, where we discuss the plan of work for the day. Two days a week we try to call into telecons with our collaborators in the US – which start at 6am local time (a challenge for me). This doesn’t always work, as the satellite service is patchy at best. This week we were only able to join for about half of each call. After our breakfast meeting, I walk the half-mile out to the telescope, work until lunchtime, walk back to the main station for lunch, and then go back to the telescope until dinner. On windy days the walk isn’t the most fun part of my day, but I’m glad to have an excuse to get outside and get some exercise. It can also be quite beautiful – we had several days of windy, overcast weather this week, which blew a lot of ice crystals into the air and produced some truly incredible sundogs.

A full-ring sundog, caused by blowing ice crystals.

A full-ring sundog, caused by blowing ice crystals.

Apart from having to get used to getting up early again, my week was actually pretty relaxed – mostly because we are still waiting for our new telescope parts. The first set of focal planes was tested at Harvard this week, which revealed that they needed a bit of rework. This means shipping them back to Caltech, which will cost us another few days. We are hoping that they will leave the US next Friday and arrive here within two weeks from today. We are also waiting for the rest of our work force to arrive. That is happening more immediately – Kirit (my fellow Harvard astronomy grad student) is in McMurdo and will hopefully fly in on Monday and Abby is only waiting on good enough weather to launch ANITA before she is able to come down as well. It will be exciting to have more people around. The BICEP3 group is growing too; four more people arrived this week, bringing our combined total to fifteen.

One of our helium compressors. These deliver helium to the refrigeration system for each receiver, to keep the telescope cold. We check the pressure every two days and add more helium if necessary.

One of our helium compressors. These deliver helium to the refrigeration system for each receiver, to keep the telescope cold. We check the pressure every two days and add more helium if necessary.

In the absence of the focal planes, my work this week has been a mix of typical Keck maintenance tasks and lab prep tasks. On the lab prep side, we have located everything we will need to disassemble and reassemble telescope receivers and have tested that all of the relevant hardware works. On the maintenance side, Grant has been teaching me everything one needs to know to keep Keck running smoothly. The most important collection of tasks happens once every two days, at the end of each observing cycle. Even though Antarctica is quite cold, our telescope needs to be much colder than the outside temperature here to get the best possible data. In fact, our focal planes operate at only a quarter of a degree above absolute zero. To keep them this cold, each receiver is connected to a special “helium sorption refrigerator” containing helium gas. (The other parts of the telescope receiver don’t need to be quite this cold but still need to be far below room temperature, so we cool them using a secondary system called a pulse tube refrigerator. Each pulse tube also contains helium gas.) The helium sorption refrigerators need to be “cycled” every two days to stay cold. While the fridge cycle is going on we can’t take data, so it is a perfect time for telescope maintenance. Maintenance tasks include replenishing the refrigerators’ helium supply if necessary, cleaning the metal track along which the telescope mount rotates, fine-tuning the telescope pointing, and checking to make sure that there is no snow inside the receivers or the ground shield. Snow removal was a big task yesterday due to the bad weather mid-week – we swept and shoveled perhaps a cubic meter of snow out of the ground shield. The most spectacular sundogs of the week appeared to reward our efforts.

Keck with sundog and secondary.

Keck with sundog and secondary.

And with that, I’m off to enjoy a lazy evening and a free day tomorrow. The weather is clearing up again, so we are all hoping for no more delays of people or cargo. Fingers crossed!

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