South Pole Weekly Report, January 25, 2009

A. Franckowiak cleaning an IceTop tank

The current IceCube population stands at 49. The population will ramp down next week as drillers/deployers start to leave early. Drilling and string installations were completed this week with the addition of strings 37, 26, and 17. This brings the season total to 19 strings safely deployed (including 1 Deep Core). Winterization activities are underway at the SES, TOS sites, OML, and IceTop. Commissioning and Verification activities are underway.

This week saw the completion of the final 2 holes of the season (hole 26 and hole 17). Hole 26 was started at 2:30am Monday morning and completed by 6:00am Tuesday morning and the weight stack was out of the hole by 8:30am. Hole 17 (the 19th hole) was started about 4 hours later at 11:30am and was completed by 6:50pm on Wednesday and handed over to deployment by 8:30pm. Flushing water out of the system started immediately after the last hole was completed and by Saturday morning the water had been completely flushed out of the system and a lot of Do Not Freeze (DNF) has already been removed from the buildings in preparation for winterizing the camp. Work is well underway to disconnect all the external hoses and cables. TOS 1 has been winterized and towed to its winter position and powered up. TOS 2 is in the process of being winterized. Firn drilling of the first 3 holes for next season has been completed using the new automated firn drilling software. All that remains is to drill next year's Rod Well hole and the firn drill can be winterized for the season. The drill crew has taken the weekend off and will commence work again with the first shift Monday morning. The drill crew is becoming smaller as drillers prepare to leave Pole. By this coming Tuesday we will be down to about 20 drillers, with most of the remaining drillers leaving Pole by Feb 4.

S. Lidstrom and D. Glowacki greet a member of the team of drivers supporting the South Pole Amundsen Omega-3 Ski Race

This week we deployed strings 37, 26 and 17. All three were quick and successful deployments that took place on swing shift, day shift, and swing/night shifts respectively. There were no special device deployments, pinger runs or dust logger runs this week. Incidentally, there is one DOM not functioning on string 26, although the DOM Connectivity Monitor (DCM) indicated it was connected during deployment. The deployment logs will have to be inspected for any unusual circumstances surrounding that DOM. All deployment supplies have been inventoried and put away for the winter. Congratulations and thanks are conveyed to all the deployers and driller/deployers who helped to make this a successful season.

This week we had no reportable injuries and no new incident reports, marking more than 85 days on the ice without a reportable injury.

The main IceTop activities were to keep the tanks clear of snow and to photograph the nearly frozen tanks to document the quality of the ice (which in all cases is excellent). As of today, one tank (06A) is completely frozen, with several others nearly so. We will start sunshade removal on Monday.

This week we deployed the final 3 strings of the season, finishing with a total of 19 strings deployed. For the cables guys from Plattville the 19th string was a special one because of the UW Platteville DOM deployed near the top of the string. One hundred and eighty-four DOMs were moved into the ICL on Tuesday, along with three drill heads and the DNF materials from the OML. The ICL is almost completely full and finding room for IceTop FCUs will be a challenge. String 26 had one DOM fail QCT. This was the first QCT failure of the season. The DOM communication problem at IceTop station 13 was fixed after replacing a patch cable in the ICL.

DOM Testing is complete. Two hundred and forty-two DOMs will remain on station over the winter, 184 stored in the ICL, the remainder in DNF storage. The OML has been winterized and powered down.

'Jack_Lightbody' was deployed on string 17 and 'Jerry Marty' on its way down.

This week we upgraded the LTO-3 tape-writing software to handle higher data rates and to make the system more forgiving of temporary high input rates. The older LTO-2 tape writing system handled the current load all week, and we're hoping to put the new system in production within the next 24 hours. We also enabled remote power cycling of the Iridium modem in the ICL for resetting the system without having to walk over from B2 in the South Pole Station. Goals for next week include tuning the monitoring of e-mail messages to make it easier to spot critical alerts, upgrading the first of four Promise RAID disk enclosures to newer, more stable firmware and configurations, and wishing Karthik a safe trip home. As soon as the Iridium OpenPort array arrives configuring and testing 24-hour network access will become a priority.

Seven new strings (6, 12, 13, 18, 19, 20 and 36) were turned over to pDAQ late on January 23rd and were verified with pDAQ in an IC40+7 run early on January 24 . In the process, the procedure for the hand-off from Low-Level Commissioning to pDAQ was tuned slightly. Attempts to upgrade pDAQ from Bay Wolf to Betelnut (release candidate 3) failed, and efforts at a fix are ongoing from the North. This effort is important to support full integration with IceCube Live, but we have managed without it so far. With assistance from the North, split detector configurations for flasher calibration runs were generated and tested on the 24th . The first Verification flasher runs were done early on the 25th. This required a slightly modified version of Bay Wolf. Operation of the flashers was smooth, but there's some question about whether the flashers behaved correctly; investigation is ongoing.

The flasher runs were collected using IceCube Live (I3Live) controlling the main partition of pDAQ. The South Pole version of the IceCube Live Web server is now online. Most functions are available and working. Switching between IceCube Live and Anvil is smooth and preserves the correct run numbering. I3Live operations carried out at South Pole are reflected on the Northern I3Live Website. This is a good start to this important upgrade to Experiment Control but there is a still lot of testing and troubleshooting to be done.

IceCube members talking to a Norwegian television crew

IceCube time was catapulted forward by one second (to the correct time) when we switched over to the backup GPS unit (this resulted in only a few minutes of detector downtime). Seven strings were commissioned this week. We are working on commissioning two more strings (the rest are not yet frozen). 16 out of 19 deployed strings have been turned on (for a total of 960 communicating In-Ice DOMs!). The first deep core string was turned on (string L = string 83). All DOMs appear to work. The high QE PMT rates are a bit higher than normal (as expected). The DOMs "Jerry_Marty" and "Jack_Lightbody" were the third-to-last and last DOMs to be deployed this season.

Some Toyota trucks pulled up to the station this week from Novo (∪2000km away). They were covering the 750km "South Pole Omega-3 Race", and those arriving included film crews from the BBC and Norwegian NRK television. They gave some of us a fun tour of their vehicles - the tire pressures are set at just 2.5 psi! Similar to 97 years ago, the Norwegians won the race and the British came second (nobody died this time, although a Bassler did go down during a support mission).

The Norwegian and British film crews received tours of the station, but they were unfortunately not allowed to film either the drill camp or the ICL.