1. Nov 30, 2003Tom Gaisser The IceTop component of IceCube Perspective from the South Pole

2. Nov 30, 2003Tom Gaisser Outline Scientific goals Design IceTop sub-group: tasks and staffing Budget & schedule Status of test-tank deployment, 03/04 season Lessons from current season

3. Nov 30, 2003Tom Gaisser IceTop: the surface component of IceCube A 3-dimensional air shower array for – Veto (i.e. tagging downward events) – Calibration – Primary composition from PeV to EeV – Calibration, composition analyses similar to SPASE-AMANDA but 5000 x larger acceptance wider energy range, better resolution IceTop at high altitude (700 g/cm 2 ) –125 m spacing between IceTop stations –E threshold ~ 300 TeV for > 4 stations in coincidence –Useful rate to EeV

4. Nov 30, 2003Tom Gaisser Small showers (2-10 TeV) associated with the dominant  background in the deep detector are detected as 2-tank coincidences at a station. Detection efficiency ~ 5% provides large sample to study this background. Showers triggering 4 stations give ~300 TeV threshold for EAS array Large showers with E ~ 100-1000 PeV will clarify transition from galactic to extra-galactic cosmic rays.

5. Nov 30, 2003Tom Gaisser IceTop station schematic Two Ice Tanks 3.1 m 2 x 1 m deep (a la Haverah, Auger) Coincidence between tanks = potential air shower Signal in single tank = potential muon Significant area for horizontal muons Low Gain/High Gain operation to achieve dynamic range Tank simulation with GEANT-4

6. Nov 30, 2003Tom Gaisser IceTop tasks & activities Design and construct tank detectors –Evenson, Shulman, McDermott, Roth, Stoyan, technician (TBH) Deploy tanks –Gaisser, McDermott, Roth, technician (TBH) Yoshida (Chiba), student (UWRF), RPSC support, Engineer (SSEC) Confirm dynamic range scheme for 2 DOMs –Bai Calibrate detectors –Bai, Stoyan, Gaisser, Clem, Niessen, Spiczak (UWRF) Develop and install DAQ firmware –Evenson, Seckel Integrate DAQ software as part of IceCube –Seckel, Software engineer (TBH), Svarnkar (grad student), Asst Prof (TBH) Simulations –Stanev, Niessen, Gaisser Reconstruction, data handling –Tilav, Post-doc (TBH) Physics analysis –All, including Asst Prof (TBH)

7. Nov 30, 2003Tom Gaisser Staffing plans Current –9 months faculty salary (includes 1 month UWRF) –10 months technical staff –5 months engineer –50 months research scientists/post-doctoral (includes SPASE, which becomes part of IceCube in PY3) –12 months grad student Additional for PY03-PY10 –4 months faculty salary (new Asst Prof) –12 months entry-level technician –12 months software engineer –12 months post-doc for event reconstruction –12 months for second grad student

8. Nov 30, 2003Tom Gaisser Budget IceTop (1.3.2) is an integral part of IceCube IceTop effort focused at Bartol/UD & UWRF –Air showers generate the primary background for IceCube as a neutrino telescope – Bartol/IceTop efforts (e.g. in simulation, DAQ, reconstruction, physics analysis) make substantial contributions to other WBS elements –1.3.2 PY3: UD $1,086K; UWRF $60K; Total $1,146K –Other WBS elements in PY3: UD: $344K Tank construction schedule: –10+32 in PY3 then 32 each in PY4,5,6 then 22 in PY7 –This schedule allows shipping by vessel after PY3

9. Nov 30, 2003Tom Gaisser Outline of Bartol/UD budget PY3 LaborCapitalMaterial & Supplies (includes shipping) 1.2.3.3 Field season ops$38K$20K 1.3.2.1 Tanks (10 + 32) 84$250K 30 1.3.2.2 Cables (local coin only) 22 20 3 1.3.2.3 DOMs (labor only) 28 1.3.2.4 IceTop specific engineering328120 1.3.2.5 Integration of SPASE 90 10 1.3.2.6 Management/office101 1.3.4.5 Test DAQ System 36 1.3.4.6 First deployment DAQ 8 1.4.3.1 Event generation 39 10 1.4.3.3 Detector simulation 33 6 1.5.1 Detector verification 50 1.5.2.1 Reconstruction 78 1.5.3.2 Calibration 26 Totals961296173$1,436K

10. Nov 30, 2003Tom Gaisser South Pole 03/04 season SPASE counting house

11. Nov 30, 2003Tom Gaisser 100 m Location of two test tanks, Nov ‘03

12. Nov 30, 2003Tom Gaisser Construction of tanks 2 Tanks delivered to Bartol in July; plumbing assembled Tanks & plumbing integrated, palletized and foamed at factory in VA late August Tanks arrive at Pt. Hueneme Sept 2

13. Nov 30, 2003Tom Gaisser Freeze-control equipment & DOMs Freeze control assembled at Bartol August - October Shipped with support equipment Sept-Oct (including sunshades) 4 DOMs with rev2 boards assembled, tested, shipped from UW October 31 Two views of freeze-control equipment mounted on tank inside sunshade at site

14. Nov 30, 2003Tom Gaisser Reassembly at South Pole Gaisser, McDermott, Roth arrive at South Pole Nov 10 Used half of 40’x15’ heated Jamesway #76 in construction/cargo area Uncrated and assembled tanks near Jamesway; location convenient to logistical support Time: 2 persons, 1.5 weeks DOMs arrive Nov 15

15. Nov 30, 2003Tom Gaisser Preparation of site In parallel with assembly –Locate & survey site –Excavating trenches: two hours using bulldozer with 14’ blade Nov 18 –Trenches 15 ft wide by about 40 ft long –Tanks separated by 10 m –Power cord from SPASE supplied by RPSC Nov 19

16. Nov 30, 2003Tom Gaisser Transport to site Nov 19 –Load tanks on sled – pull across skiway to MAPO –Forklift from MAPO to site –Level bottom of trenches –Set & level tanks –3-man RPSC crew took a total of 2 hours

17. Nov 30, 2003Tom Gaisser Install freeze-control & DOMs Tank10 (1.0 m ice) –Install freeze box –Install ejection pipe –Bring up software –Install DOMs –Nov 20-21 Tank09 (0.9 m ice) –Same procedure –Nov 25-26

18. Nov 30, 2003Tom Gaisser Fill tanks Tank10 –Freeze up of hose on first attempt (Nov 21) –Successful fill Nov 22 20 minutes to fill < 10 RPSC man hours for transport and filling Tank09 –Filled Nov 26, very smooth operation

19. Nov 30, 2003Tom Gaisser Monitor freezing Two days to freeze over –Frost-covered ice –Clear; wind 6-10 kts –T = -40 to -35 deg C –Ice-surface at -20 deg C  37 days to freeze 1 m But Tank10 at 2/3 ideal rate Will reduce heat tape, pump cycle time, add fans to reduce freeze time Tank09: problems with temp sensors currently being addressed. No water ejected after 100 hours suggests slow leak. To be investigated. Ice appears good. Winter-over scientist will take over monitoring to bridge until arrival of next crew (J. Eisch, S. Yoshida)

20. Nov 30, 2003Tom Gaisser Remainder of season Dec 1-5: train winter-over scientist (J. Lackey) and address problems Dec 10-30: Monitoring continues –S. Yoshida, Dec 10-31; J. Eisch Dec 20-Jan 6 Dec 29-Jan 20: Install DOM-DAQ –J. Kelley, A. Karle with Evenson & S. Tilav Jan 12-27: Close tank –P. Evenson, Jan 12-27

21. Nov 30, 2003Tom Gaisser Lessons so far Modularize equipment –“plug and play” design to reduce labor needs – Programmable Logic Control to streamline assembly and operation Should include temperature control of heat tape Commercial OTS control units at each tank –See memo of Andrew McDermott based on experience this season Manufacturing schedule should be at least one season ahead to allow shipping by vessel Need full Jamesway (40 x 15 ft) for staging Begin early in season with tank assembly Counting house, surface cables required early to allow setting tanks Tanks to be filled as soon as Rodriquez well for drilling is ready—should not wait to be filled as each hole is drilled.