It's Starting to Get Real

     Hi everyone!  Sorry for the long delay between posts.  Things have been super busy in the lab while we get ready to deploy.  It's been an eventful couple of weeks.  The camera receiver shipped to the Pole earlier today and that means we're really close to deploying this experiment!  The receiver is the cryostat that will house the camera and much of the passive readout electronics, all of which has to be cooled to 4 K or below (-452.5 F) to operate.  The detectors actually sit much colder than this, at only 280 mK (0.28 K, or -459.3 F).  That's really cold. 0 K is absolute zero, the point at which all motion stops, so we're only 1.3 F away from as cold as you can possibly get... period.  With some rare exceptions, (like when the CMB gets absorbed by clouds of, say, formaldehyde), the coldest any place in the Universe gets is 2.7 K because the CMB is 2.7 K.  In general, if some gas cloud or whatever were to get colder CMB photons would just re-thermalize it to 2.7 K, so the Universe is pretty much locked to whatever the CMB temperature is.

     All of this means that our receiver (when in operation) is literally and figuratively one of the coolest places in the Universe.  If the current cosmological model holds true, it will take another 36.2 billion years of expansion for the Universe to cool to our operating temperature.  I mean... the Universe is only 13.76 billion years old.  It's a mere teenager right now, and it will be 50 [billion] years old when it has finally cooled down below our receiver's temperature.  (For those interested, the lowest temperature ever reached in a laboratory was 100 pK, or 1x10^-10 K.  That's 3 billion times colder than what our camera will be in operation).  A couple pictures of the camera and the camera installed in the receiver cryostat when it was still in Chicago are below.

A backside view of the SPTpol camera (receiver). The back end of one of the 150 GHz camera modules I designed can be seen installed (the tower with the red circuit board). The green circuit boards will have 192 individual 90 GHz pixels soldered on from the front side. Most of the holes in the circuit boards are for alignment pins to hold the pixels in exactly the right locations.

A view of the receiver installed in the receiver cryostat. While the camera itself is really cold, it can't just float in space - it has to eventually be connected to the rest of the world. This means to stay cold on the camera end all the readout wiring has to be clamped and thermally sunk at several temperatures on the way from 280 mK to 300 K (room temperature). Those awesome star-shaped hex rings provide clamping area to do just that.

     But the REALLY exciting news is that I have my plane ticket information for my trip to Antarctica!  The receiver team (that's me, a grad student from Berkeley named Liz, a grad student from Chicago named Abby, and a post-doc from Chicago named Brad: we get to actually install the camera) has been waiting for confirmation that the receiver worked and could cool and operate detectors properly.  That milestone was reached last week at Chicago, and with the receiver shipping out to meet us at the Pole we got the okay from the higher ups of SPTpol to allow Raytheon to ticket us last Friday.  I got my flight information yesterday and...  I officially leave for the South Pole next Thursday, December 1.  It's going to be quite the adventure....

     I start out leaving Denver at 4:40 PM Mountain time (Thursday Dec 1) to arrive in Los Angeles at 6:20 PM Pacific time.  I'll be hand-carrying four of seven camera modules I've built as carry-on.  They're way too precious to pack as checked baggage.  Liz will have the other three since they'll be in Berkeley being tested until we leave next week.  I then have a 5 hour layover at LAX.  I think at that point I'll be meeting Liz, Abby, and Brad since we're all on the same flights from there on out.  The next leg is the longest - a 13.5 hour flight from Los Angeles to Auckland, New Zealand (the north island).  We take off at 11:25 PM Thursday, Dec 1 and arrive at 9:50 AM Saturday Dec 3.  The flight might be only 13.5 hours, but New Zealand is 20 time zones ahead of me in Colorado (and 21 ahead of LA).  I'll lose nearly an entire day going over the International Dateline.  How messed up is that?  It's a crazy world.

     From there it's pretty easy going.  I take off from Auckland that same day at 12:10 PM and arrive at 1:35 PM in Christchurch, NZ (the south island).  Christchurch was in the news earlier this year when it was hit by a pretty major earthquake.  I think it was the second-largest natural disaster in New Zealand's history - really sad.  A lot of people were killed and a lot of old/iconic buildings were damaged or destroyed.  Thankfully it wasn't any worse.

     I'm in Christchurch for a couple days, and while there I'll get all of my ECW (Extreme Cold Weather) gear for life at the South Pole.  Then I just wait for a phone call confirming my flight to McMurdo station on the coast of Antarctica, which will be the morning of Dec 5 (Dec 4 back in the US).  I'm at McMurdo for a day and then I have my fifth and final flight on Dec 6 when I will finally reach the South Pole, weather permitting.

     This is going to be crazy exciting and I'll be taking pictures and telling everyone about the trip very soon.  In the next week I hope to post a couple more entries on the science, instrumentation, and technology to finish up all the background material and give everyone a decent sense of what we're doing, how we're doing it, and why.  I'll be busy with final lab preparations and packing, though, so no promises.  In any event, this blog will FINALLY have an entry about my actual experiences at the Pole in just a couple weeks.