Drilling operations have been proceeding smoothly. Eleven holes were drilled and strings deployed by January 14. The ICL is effectively commissioned. All strings from last year are powered up. Special devices have been deployed. Commissioning in progress.
The IceCube population is currently at the level of 48, as of January 14. There are 28 drillers and 20 other population, which includes winterovers, IceTop, deployment, cables, counting house and data systems.
Excellent progress was made in drilling in the past week. By Monday, January 22, 17:00h the 11th hole of the season has been drilled. Drilling has been going reasonably steady. There were some glitches and problems to work through. During the drilling of the 10th hole a segment of the hose had to be replaced because of a leak. The leak grew significantly and an increasing amount of water was lost before the hose unspooled to the point when it could be replaced. The replacement procedure went well and took about one and a half hours. Quite a few pictures were taken of the steaming reel. It should be mentioned that the drill lead and the drill crew did at no time feel that the leak was dangerous and expected the hose strength member to still be intact, which it was.
An important milestone was achieved on January 22 when a new firn hole was drilled with the new independent firn drill, which was designed and built at the PSL (IFD). This drill operates entirely with electrical power and can therefore be operated independent of the hot water drill system. It circulates a mix of water and glycol to the drill head and operates with 100 to 150 kW of electrical power. The advantage is that the firn hole could drill hole number 12 at the same time while deep ice drilling was performed on hole number 11 using the enhanced hotwater drill (EHWD). The drill lead estimates that 12 to 15 hours could be saved in every cycle.
All surface cables are attached to the patch panels and DOM Hubs. Deep strings have been attached and tested shortly after deployment.
The ICL is commissioned. There was a ribbon cutting ceremony with NSF and Raytheon on Saturday January 20, 2007. The Temporary IceCube Lab (TICL) is cleared out and decommissioned effective January 19. The microwave link to the drill camp has been moved to the ICL. The TICL has been powered down. Good progress os being made on installation of P-DAQ software in preparation of P-DAQ team arrival. Firmware upgrade of GPS was performed. ICL antenna box and conduit for antenna cables was completed and antennas installed in box.
To date, all of last year's DOMs have been successfully powered up. String 38 was the first string to be commissioned. It passed all of the Testing DAQ tests. To date five of the new strings have been powered up.
Everything is going well with IceTop. All new tanks a still open and will be freezing in this mode for another ~10 days.
One Bubble camera has been deployed. Its purpose is to observe the quality of hole ice after the freeze in. Two acoustic detector strings with 7 sensors each have been installed so far. One more is to be deployed on Jan 22. Two radio sensors have been deployed at 1400m and at shallow depth. One more calibration unit is to be deployed on Jan 22
Dom testing cycle 15 ended a couple of days ago. We have now enough DOMs for 13 strings. A set of 26 DOMs is being tested for backup and fault analysis. In a couple of days the shutdown will begin.
A delegation of New Zealand and U.S. officials visited the South Pole this week. Among the group were Helen Clark, Prime Minister of New Zealand and Dr. Arden L. Bement, Jr., Director, National Science Foundation and Official Host of the Delegation.
The visitors were very interested in science and spent a fair amount of time on science projects in the dark sector, namely the 10 m Telescope and IceCube. They were impressed with the science and construction activities. Dr. Bement was in particular impressed by the state of readiness of IceCube for science data, which was illustrated by the highly instrumented ICL.
A number of expeditioners came through last week. Among them was a team of three women who traveled 1200 km in 54 days to the Pole. The group was guided by the Canadian expeditioner, Denise Martin.