South Pole Weekly Report, December 7, 2008

The total IceCube population stands at 51. The big news of the week is completion of the first hole of the season and the deployment of String 18 on December 5 local time. Nearly all IceCube cargo for the season had arrived by December 4, including the Paro pressure sensors required for deployment.

Start of drilling at Hole 18, December 3, 2008

Photo by J. Haugen

The assembly and testing of the drill in preparation for drilling was completed by around Tuesday and the drillers held a meeting to discuss readiness for drilling and any issues of concern remaining. The meeting determined that the drill was ready. An emergency response drill was held on Monday as a precursor to drilling. IceCube management and Raytheon personnel met on Wednesday to discuss readiness of the drill system, deployment readiness and Raytheon support availability. All agreed that everyone was ready and formal approval for drilling was given that day.

Action at Hole 36 on December 6

Photo by T. Gaisser

Drilling of the first hole of the season (hole no. 18) commenced at around 10:30am on Wednesday Dec 3rd. Drilling proceeded smoothly with no major hiccups and was completed by the end of second shift (around 11:30pm on Dec 4). Deployment began soon after and cable drag was completed by 3:00pm on Dec 5. Work on TOS 2 to make it ready for drilling was completed on Dec 5 and drilling of hole 27 started at approximately 11:15pm on that day. Drilling is proceeding smoothly and as of Sunday afternoon the desired depth had been achieved and the drill is nearly back to the top. The drill system appears to be performing pretty well so far. We have good communications with the drill head. The new fuel day tank appears to be functioning very well and providing steady fuel flow to the system. Some minor problems with sensors were quickly resolved. All in all the system appears to be performing more reliably than it has in past seasons. Firn drilling is proceeding smoothly, but still in manual mode at this stage. Hole 37, the "Pork Chop" hole remains problematic. After moving it a few metres from its original location more debris was encountered and a new location will have to be found. As of Saturday, December 6, we have 7 firn holes completed, which puts us about 5 firn holes ahead of the main drilling.

Depth by pressure (red line) for Hole 18

We had our combined IceCube/RPSC Emergency Drill December 1. It went very well from both sides. We learned two lesson from this activity. The original 911 call from the Drill Camp went to Medical instead of COMMs because the lines were still set in Winter mode. That has since been corrected. One other lesson learned is that during an emergency, especially when someone is injured, the Shift Lead and the DCC Operator must be in communication. In this way, when the OSC from the first team arrives, he can be completely briefed by the DCC Operator with the emergency status. Further, everyone would then know where the Shift Lead is, as well.

We continued with our Safety Assessments this week. Earlier, the Cable Pulling process was audited at the ICL. That was an impressive operation. It seems that we used 15 people in order to massage that cable along an s-curve path to get it up to the second floor of the ICL. Everyone seemed to know about the process and were safe at their positions. The auditor had watched the first four cables get pulled up and was about to call it quits, when the group took a break. At that point, about half of the folks left. The auditor was then requested to help out! Well, it is a lot easier to understand a process by participating in it. Those surface cables are a lot heavier than they look. The auditor gained a huge amount respect for those persons involved in cable pulling. At the Drill Camp, we completed the final equipment tests in preparation for drilling.

Day-shift deployment team with the last DOM on String 18.

Photo by T. Ham

The deployment started at 4am on December 5th and involved a shift changeover at 7am for the day shift to take over from the night deployment shift. The total deployment which included a complex final drop took approximately 9 hours. The Paro sensor worked extremely well and helped us establish a final hole depth of 2452m. Data from a new deployment load cell that was added over the summer was very helpful in effectively reaching the final well depth.

In the last week of DOM-testing we completed the South Pole Acceptance Test (SPAT) 8 without any problems. SPAT 8 consists of 64 regular DOMs (in ice) of which 60 will be deployed in String 37. No DOMs have failed during this SPAT. There has been no additional SPAT, because there was no empty sled available during this week.

This was a very busy week for all of IceCube as many milestones were reached. Six surface cables were pulled into the 2nd floor of the ICL on Wednesday, Dec 3rd, including the Low Energy surface cable. On Friday, 4 surface cables were laid into Trunk #2 and a total of 9 Surface Junction Box (SJB) surface cables were connected to SJBs. Sixteen of 27 ParoScientific depth sensors were tested and OK'd for deployment. The balance will be tested this week. The second cable pull of 4 cables is scheduled for Monday afternoon. Trenching of Trunk #3 is scheduled to start on Tuesday or Wednesday with another cable pull of 5 cables anticipated for late in the week.

T. Hannaford and M. Kleist bringing Trunk 1 cables into the East Tower.

Photo by J. Haugen

This week we celebrated the completion of the first phase of the IceTop season. Preparation of all of the IceTop tanks was completed. Calibrations were completed on all 38 Freeze Control Units (FCUs) that will be used this season. Now we move on to the next phase of tank filling. The first 6 surface cables (including one to the first deep core location) were pulled into the ICL early in the week. The five cables to IceTop stations were connected to IceTop power and communications at the tanks, and to the IceTop DOM hubs in the ICL. This milestone permitted the beginning of IceTop tank filling operations. With deep drilling underway and a good Rodwell established, glycol concentrations are low in the water supplied from the drill camp, below the detectable range. The first IceTop tanks at hole 6 were filled on Dec. 4th, one day ahead of schedule; filling continued at 4 tanks a day. As of Dec. 6th, all ten of the trunk 1 IceTop tanks were filled. As testament of the quality of the work that was done preparing the tank enclosures, all 10 FCUs are operating at set-point temperature while using only the first stage of the three stage heating system.

C-17 air-drop

Photo by H. Kolanoski

In the past week the processing and filtering storage was added, and the new SPADE (data processing) servers were commissioned. We finalized maintenance and upgrading all network devices. Work on reconfiguring rack 15 to support inner core hubs was started, and hopefully with the transition to new DAQ servers this work can be completed in the coming week.

The goal of the work on AMANDA was to document the status of the hardware and the functionality of the software so that AMANDA data during the IC40 run can be correctly interpreted.

Saturday, Dec. 6 between 18:45 and 20:00 local time there were two air drops and several fly-bys from a U.S. Air Force C-17. The plane loaded and took off from McMurdo and returned directly to Christchurch. The temperature reached a high enough level (-35° C) so the Ford "Gran Neutrino" IceCube shuttle with mat-tracks could return to service.