This was a big week for IceCube. The first hole of the season was successfully completed on Friday, December 7, and String 63 was deployed during the night and tied off Saturday morning. Cables for the first three trunks were pulled into the ICL this week and connected. We also filled the first eight IceTop tanks (Trunk 1). We are all especially grateful for the excellent and hard work of the drill team.
Fifty IceCube staff are at Pole this week. Cargo deliveries for IceCube are up to schedule with a total of over 341,000 lbs of equipment at Pole week ending 12/9/07. We have one shipment currently air shipping to Pole containing replacement components for the drill and ICL. The Northern Hemisphere Support Group is handling some requests from Drilling.
Drilling commenced on Wednesday Dec 5, at around 4:30am, about 3 days behind schedule, but still 6 days ahead of last year's start of Dec 11. Despite a few teething problems with the new software, winch brake problems and some problems with our fuel delivery system, drilling was completed at 7:00pm on Friday Dec 7. Deployment commenced at about 10:30pm that night and was completed in around 10 hours.
The drilling equipment was moved to hole on Saturday Dec 8 and the equipment prepared for drilling. We expect to commence drilling hole 2 in the early hours of Monday Dec 10, after the driller day off on Sunday.
At this stage we are happy with the state of most of the equipment, except for some air problems in the fuel system which we are working on. A few bugs discovered in the new software have been attended to and we are working on one remaining issue, but this won't delay drilling. The hose doesn't appear to have any leaks and we have not encountered any defects in it at this stage which would require a section to be replaced.
The crew are all healthy and in pretty good spirits. The installation for Hole 63 was completed at 9:07am on Saturday when we removed the load from the load cell by securing the Surface to DOM cable to a deadman anchor. The deployment was started at 11:07pm on Friday when the installation of the DOMs began. The deployment took 10 hours.
Standard Candle. Standard Candle 1 (deployed 2 years ago) was successfully powered on (without firing the laser) for a communications test. Preparations to deploy Standard Candle 2 in String 55 (3rd) are underway. The software running inside the device was successfully updated to reconfigure the IP address. Impedance baselines were measured in preparation for leak testing after deployment. Although the alignment looks reasonable by eye, light meter measurements indicate a 20% azimuthal asymmetry. Before shipping the alignment was within 5%. Efforts are underway to achieve this level of alignment again.
Dust Logger. All cargo is in the ICL. The team will assemble, test, and log holes in January
South Pole Acoustic Test Setup(SPATS). An increase in the overall noise level was observed in all channels of all three deployed SPATS strings, during deep drilling of the first string. No increase was observed prior to this due to drill camp or other surface activity, so this is likely due to ice cracking and popping at the water-ice interface in the hole. This season there are two projects continuing the three strings that were deployed last year. SPATS String D will be deployed on an independent cable similar to the first three (with length increased from 400 m to 500 m), on String 76 (6th). Modifications of the SPATS Master PC in the ICL, necessary to communicate with and control String D, have begun. Sensor and transmitter testing for String D will begin soon.
DOMs for string 63 were unloaded from the sled to make possible start of test cycle 9 this week. A great effort was made by many IceCube team members to carry 45 DOMs stored in B2 Science to the Alpha doors. The set of DOMs for hole 71 (season's fourth) is now ready for pick-up. Four DOMs were failed before and during deployment of string 63. Buffer size is now 137 DOMs.
We pulled 11 cables into the ICL and 8 of these cables were connected to patch panels. This completed the installation of IT stations #62, #54, #63, #45, #75, #76, #69 & #70 from Surface Junction Boxes (SJBs) to DOR (Dom Readout) cards. We placed SJBs in the remaining 6 IT trenches. We found two cables to be too short to reach from the ICL to their respective SJBs in the IT trenches. We were able to swap these cables with longer cables. The cables swapped were: #75 swapped with #76 and #60 swapped with #68. All of these cables entered the ICL and were connected to patch panels.
Inventory was taken of all incoming cables from this year. Work was started on preparing the DOM Connectivity Monitor (DCM) to assist with DOM deployment and all incoming ParoScientific pressure sensors were tested for use this deployment season.
FCUs (Freeze Control Units) were installed on the eight IceTop tanks on Trunk 1. Contactor assemblies were installed in the tanks and the prefill checklist was completed. Tank filling commenced with station 62 on Thursday Dec. 6th, only one day later than scheduled. Station 54 was filled on Friday and two stations, 63 and 45 were filled on Saturday putting IceTop on schedule. Sunshades were installed on Station 62 Saturday and the tanks were opened to begin the freeze. All tanks have stable temperatures and are working properly.
IceTop had a remarkable week. Thanks to Terry Hannaford and the NHSG, fan units required to repair the IceTop Acopian Power Supplies arrived here six days from placing the order. All 10 IceTop supplies are now in service and have been installed in the racks in the ICL.
Eleven surface cables were run from the IceTop trenches to the ICL. The surface cables were connected both at the SJB and at the ICL patch panels. Trunks one and two were connected to the DOM hubs and all DOMs for the IceTop tanks on these trunks passed their commissioning tests.
Water testing continues to be excellent with typical results showing less than 1 ppm glycol in the filtered water.
Next week we will continue to connect the remaining surface cables to SJBs and in the ICL. The trunk four surface cable will be pulled. Tank filling will continue.
ICL - Hubs installed and configured for IceTop fill activities. Work continues on cabling UPSs and In-Ice Hubs. Taping system moved from ICL to B2 science.