The Ice Top component of Ice Cube Perspective

The Ice. Top component of Ice. Cube Perspective from the South Pole Nov 30, 2003 Tom Gaisser

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

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

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

Ice. Top 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 Nov 30, 2003 Tom Gaisser

Ice. Top tasks & activities • Design and construct tank detectors – • Deploy tanks – • Stanev, Niessen, Gaisser Reconstruction, data handling – • Seckel, Software engineer (TBH), Svarnkar (grad student), Asst Prof (TBH) Simulations – • Evenson, Seckel Integrate DAQ software as part of Ice. Cube – • Bai, Stoyan, Gaisser, Clem, Niessen, Spiczak (UWRF) Develop and install DAQ firmware – • Bai Calibrate detectors – • Gaisser, Mc. Dermott, Roth, technician (TBH) Yoshida (Chiba), student (UWRF), RPSC support, Engineer (SSEC) Confirm dynamic range scheme for 2 DOMs – • Evenson, Shulman, Mc. Dermott, Roth, Stoyan, technician (TBH) Tilav, Post-doc (TBH) Physics analysis – All, including Asst Prof (TBH) Nov 30, 2003 Tom 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 Ice. Cube in PY 3) – 12 months grad student • Additional for PY 03 -PY 10 – – – 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 Nov 30, 2003 Tom Gaisser

Budget • Ice. Top (1. 3. 2) is an integral part of Ice. Cube • Ice. Top effort focused at Bartol/UD & UWRF – Air showers generate the primary background for Ice. Cube as a neutrino telescope – Bartol/Ice. Top efforts (e. g. in simulation, DAQ, reconstruction, physics analysis) make substantial contributions to other WBS elements – 1. 3. 2 PY 3: UD $1, 086 K; UWRF $60 K; Total $1, 146 K – Other WBS elements in PY 3: UD: $344 K • Tank construction schedule: – 10+32 in PY 3 then 32 each in PY 4, 5, 6 then 22 in PY 7 – This schedule allows shipping by vessel after PY 3 Nov 30, 2003 Tom Gaisser

Outline of Bartol/UD budget PY 3 Labor 1. 2. 3. 3 Field season ops $38 K 1. 3. 2. 1 Tanks (10 + 32) 1. 3. 2. 2 Cables (local coin only) 1. 3. 2. 3 DOMs (labor only) 1. 3. 2. 4 Ice. Top specific engineering 1. 3. 2. 5 Integration of SPASE 1. 3. 2. 6 Management/office 84 22 28 328 90 101 1. 3. 4. 5 Test DAQ System 1. 3. 4. 6 First deployment DAQ 36 8 1. 4. 3. 1 Event generation 1. 4. 3. 3 Detector simulation 39 33 1. 5. 1 Detector verification 1. 5. 2. 1 Reconstruction 1. 5. 3. 2 Calibration 50 78 26 Totals 961 Nov 30, 2003 Capital Material & Supplies (includes shipping) $20 K $250 K 20 30 3 120 10 10 6 296 Tom Gaisser 173 $1, 436 K

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

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

Freeze-control equipment & DOMs • Freeze control assembled at Bartol August - October • Shipped with support equipment Sept-Oct (including sunshades) • 4 DOMs with rev 2 boards assembled, tested, shipped from UW October 31 Nov 30, 2003 Tom Gaisser Two views of freeze-control equipment mounted on tank inside sunshade at site

Reassembly at South Pole • Gaisser, Mc. Dermott, Roth arrive at South Pole Nov 10 • Used half of 40’x 15’ 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 Nov 30, 2003 Tom 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 Nov 30, 2003 Tom 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 Nov 30, 2003 Tom Gaisser

Install freeze-control & DOMs • Tank 10 (1. 0 m ice) – – – Install freeze box Install ejection pipe Bring up software Install DOMs Nov 20 -21 • Tank 09 (0. 9 m ice) – Same procedure – Nov 25 -26 Nov 30, 2003 Tom Gaisser

Fill tanks • Tank 10 – 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 • Tank 09 – Filled Nov 26, very smooth operation Nov 30, 2003 Tom 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 Tank 10 at 2/3 ideal rate • Will reduce heat tape, pump cycle time, add fans to reduce freeze time • Tank 09: 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) Nov 30, 2003 Tom 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 Nov 30, 2003 Tom 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 Mc. Dermott 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. Nov 30, 2003 Tom Gaisser