1. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser1 IceTop IceTop station 2004 test tanks Calibration Verification 04/05 DOM operation Summary (Season plan)

2. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser2 IceTop DAQ must capture three classes of events in 04/05: Single particles (low-energy e ±, ,  for tank calibration) –Remnants of low energy interactions –~ 2.5 kHz for 30 MeV threshold (10 pe) –Muons deposit 200-300 MeV (70 pe) Small showers (few TeV for tagging single  in deep-ice) –Typical source of  background in deep detector (E  ~ 0.5 TeV initially) –10-20 m footprint on ground Coincidence between two tanks at a station No signal in neighboring stations No IceTop trigger Check each in-ice event for such surface activity Large showers that trigger IceTop (E > 300 TeV for air showers and muon bundles in deep-ice) – 3 or 4 stations hit in ~300 ns window –Primary energy up to 10^7 GeV with 4 stations [ Horizontal multi-m events (later in year or next season) ]

3. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser3 IceTop Detector 2 m 0.9 m Diffusely reflecting liner

4. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser4 IceTop station Two Ice Tanks 2.7 m 2 x 0.9 m deep (scaled-down version of Haverah, Auger) Integrated with IceCube: same hardware, software Coincidence between tanks = potential air shower Local coincidence with no hit at neighboring station tags muon in deep detector Signal in single tank = potential muon Significant area for horizontal muons Low Gain/High Gain operation to achieve dynamic range Two DOMs/tank gives redundancy against failure of any single DOM because only 1 low-gain detector is needed per station ~ 5-10 TeV

5. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser5 Feb 10/11, 2004 Tank 9 with  telescope Tank 10

6. 1 2 3 4 5 6 Tank10 Temperature Sensors 9 Feb 04 9 Apr 04 19 May 04 5 4 1,2,3,6 Tank9 DOMs Tank10 DOMs indicates cold start air DOM MainBoard Temperatures 18 Jul 04 Note that -Tank9 is still 3 deg colder than Tank10 - MB temps 10 deg warmer than ice in normal operation - Glass temp tracks MB temps, warmer by only 5 o - Glass and MB reaches ice temps at cold start - Tankice temps 6 deg warmer than snow - snow temps 10 deg warmer than air http://icecube.bartol.udel.edu/DOMMonitor/DOMTemps.html 8 Sep 04 3 Oct 04 -55 o

7. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser7 Tank 2001 (buried under snow— different temperature sensors)

8. VEM

9. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser9 Tank calibration & monitoring Use characteristic spectrum with muon peak and high-energy tail –Requires calibration data stream –Requires lab station for data template (two water tanks at UD) –Requires detailed simulations of response of tanks to Photons Electrons muons

10. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser10 Test tanks for calibration: Full station at UD, 1 tank at UWRF Test tank at UWRF with AMANDA OMs

11. Fig 1 John Clem, FLUKA

12. Fig 4 Set discriminator threshold here John Clem, FLUKA

13. The simulation results are shown as histograms. The dashed green histogram is proton fluxes determined with a higher modulation level primary spectrum. Solid red circle is Bai et al. 2001 measurement. All other data shown is from Grieder 2001. The dashed red line muon measurement at 3250 meters elevation and solid red is 2960 meters. Red diamond 700mbar pressure. Black line is gammas at 750mbars (measurement at unknown geomagnetic cutoff and mod level). Green line is protons at 3250 meters and green circle at 700g/cm2 (cutoff and mod level unknown) John Clem, FLUKA Comparison with measured flux

14. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser14 Verification 04/05 Obtain charge spectrum from high- gain DOM in each tank Obtain rates of station hits and coincidences –station hit = both tanks hit within 100 ns –1-folds, 2-folds, 3-folds, 4-folds in 500 ns Zenith and azimuth distributions Coincidence rates with deep detector

15. Simulated response of single station hits (mostly single muons in deep ice) Low coincidence rate is due to 4-string geometry,  < 6 o in ‘05

16. Core location distributions, E p =18 TeV

17. Core locations for E p = 2.7 PeV Note that ring of distant singles from PeV showers will be removed by surrounding stations in larger array

18. E p, cos(  ) distributions of 4-folds 3-fold rate ~ 0.30 Hz

19. 0o0o 90 o Azimuthal distributions

20. Spectrum of deposited energy for 4-fold events (VEM*factor)

21. 13,24 -200,-220 210,220 -53,-71 Numbers in boxes show hit times in ns relative to core time of ideal shower plane

22. IceTop DOM settings Set voltages so  peak is centered on ATWD0 of HG DOM and on ATWD2 of LG DOM Require local coincidence between tanks to keep data rate low Short calibration runs to collect single tank particle spectra

23. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser23 Summary We are on track for 8 tanks in PY3 Ongoing temperature measurements clarify operating range for IceTop DOMs Operation of DOMs requires –Local coincidence (or high threshold) –Implementation of DAQ & data handling –Parallel studies with test tanks in labs at UD and UWRF –Simulation studies in parallel for calibration, event reconstruction (Peter Niessen’s talk)

24. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser24 Nominal layout of IceTop Minimize deviations from nominal 125 m grid

25. Station configurations for 04/05

26. IceTop Station and Surface Junction Box Interface to IceCube System 24VDC +/-48VDC Freeze Controller Temporary Smurf Cables 2 +/-48VDC Cables 1 RS485 Data Cable Surface Cable from Counting House Surface to DOM Cable From Hole Surface Junction Box IceTop Excavation NOTES: 1. Drawing is in approximate relative scale. 2. Tanks are 10 meters between centers. 3. DOM cables are 17 meters long. 4. RS485 Master source is controlled by plugging in the desired data cable. 5. Tank power source is controlled by plugging in desired power cable. 6. Power Converter contains +/-48VDC to 24VDC converter and EMI filter. George Anderson Sept 17, 2004 File Rev F Power Converter (green box)

27. 04/05 IceTop schedule * Power required ** Water required Dec 1 Dec 10 Dec 20 Jan 6 Connect to TCH Fill tanks Jan 20 Feb 3 Backfill Cover tanks Run DOMs Evenson 12/4 – 12/27 Gaisser 11/26-12/14 Tilav 1/12 – 2/1 Roth 11/26-12/16 Jamesway SMURF TCH Lundberg 12/17-1/13 Kelley 12/17-1/18

28. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser28 SMURF = temporary temporary counting house to provide power, & monitoring of freeze control ~ 12/1 to 1/15 when TCH is ready

29. Some events

30. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser30 time in 25 ns bins  calibration in Auger events muon charge distribution 3 PMT avg traces

31. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser31 Muon self-calibration procedure Take in-tank coincidence data for each tank for commissioning Compare to lab template (in water) Interpret deltas with simulations Fix parameters for interpretation of signals Add to data base Vertical  (defined by  -telescope) In-tank coincidence (defined by 2 OMs) broadened  peak + low energy e-m background Data with test-tank setup at UD in water. (Large negative amplitudes on left.)

32. IceTop Collaboration Meeting Uppsala, Oct. 9, 2004Tom Gaisser32 Compress by ~10 for IceTop