December 17, 2008, South Pole Station -- James Roth
Passing the Baton
The 2008–09 IceTop season is winding down for me! It has been an incredible season. So far we have filled 32 of the planned 38 IceTop tanks. It is clear now that we will finish the tank-filling phase on schedule. It will now take the next 53 days for all of the IceTop tanks to become frozen blocks of clear ice. Once frozen, the tanks will be closed and made dark, the Digital Optical Modules (DOMs) will be turned on, and the search for cosmic ray particles will begin.
Yesterday, the last trunk of surface cables was connected in the IceCube lab for this season. I have mentioned before how important these surface cables are to IceTop. In addition to carrying the signal from each DOM to the IceCube lab, the center of the cable carries the power required by the freeze control units (FCUs). By the end of the season there will be a total of 3,360 DOMs deployed in the deep ice, and 236 IceTop DOMs deployed. The total length of the deep-ice cables and the surface cables deployed by the end of this season will be over 105 miles!
Cables being connected in the IceCube Lab. Photo by James Roth
Len Shulman arrived today, and he brought darkness at the end of the tunnel! With 24 hours of sunlight for the last 40 days or so, I’m looking forward to my first sunset in New Zealand.
Len Shulman arrives at Pole. Photo by James Roth
Len will now be responsible for monitoring the status of the 38 IceTop tanks as they freeze. He will need to install the sunshades and open the lids of the last 10 tanks filled after the three-day period that we allow for the water to cool down and for the FCU to remove a good portion of the dissolved gasses from the water. He will also guide the backfilling of the IceTop pits as the “in ice” cables are connected.
Jens installs a sunshade just before opening an IceTop tank. Photo by James Roth
We will have only two days as Len gets acclimated to the altitude to discuss how things have gone and to share ideas about any problems we might have. Len designed the electronics for the FCUs, so he has a complete understanding of the operations. I feel relaxed to leave things in Len’s capable hands.
