IceTop Status: 1 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Status of IceTop: 3.2 Bartol Res. Univ. Delaware: Tom Gaisser, Xinhua Bai, Paul Evenson, David Seckel, Todor Stanev, Serap Tilav, Ralf Ulrich Univ. River Falls: Jim Madsen, Glenn Spiczak Status Plans Measurement of Horizontal Muons

IceTop Status: 2 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Tasks for Project Year 1 Collaboration Mtgs ( ) IceTop (3.2) –Tanks –IceTop Specific Engineering System Design Simulations

IceTop Status: 3 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceCube Deep Array: InIce Surface Array: IceTop Where’s the muon ?

IceTop Status: 4 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Science Goals Surface Veto for InIce –Core contained Full Veto E s > 30 TeV Partial Veto (5 %) E s > E s, m (3 TeV) –Core outside IceTop “Vertical” – e, g E s > 1 PeV q < 60 deg “Horizontal” - m E s > 100 PeV q > 60 deg Calibration Beam for InIce (E, q ) Muon Bundles, E s > 300 TeV Cosmic Ray Composition Detection by IceTop (e, g ) and InIce ( m ) Contained E s > 300 TeV Real time - access - to data Reconstruction: IceTop Trigger

IceTop Status: 5 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Requirements Science requirements (outlined in preliminary IDD – but not finalized) Detector requirements: should go into System Design Documents

IceTop Status: 6 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Station Schematic Two Ice Tanks 3.6 m 2 x 1 m Two DOMs: 10” PMT High Gain w/station coincidence: 1 p.e. resol Low Gain: 1 m resol To DAQ IceCube Drill Hole ~15 m HG LG

IceTop Status: 7 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Data Types Single “Tank hits” (Muons + E e > 30 MeV) –id (2), time (4), fit parameters(6) – 12 bytes –2500 Hz * 12 B = 30 KBps/DOM Soft Component: “Station hits” –Check for local coincidence (two tanks) –R showers ~ Hz –R uncorrelated coincidence ~ Hz –Mostly simple fits – 2 KBps/DOM Waveforms –95% consistent with impulsive event: FX data only –5% not impulsive, return compressed waveform: CWF ~ 100 B rate 100 Hz + Scaled selection of minimum bias events ~ 10 Hz 200 Hz * 100 B = 20 KBps/DOM

IceTop Status: 8 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA DOM truth tables

IceTop Status: 9 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Data Handler IceTop Data Handler HG Chan LG Chan. Tank 1 LG Chan HG Chan Tank 2 Station 1 Station 2 Station 80 DOM Hubs IceTop Data Handler (aka SP) Vert. Sh. Trigger Global Trigger InIce DATA InIce Trig.Gen. On line ICETOP DAQ Hor. Sh. Trigger Common Event Builder DAQ Control Monitoring

IceTop Status: 10 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Overview of Design Process PY 1: 4/1/02 – 3/31/03 –Integration of IceTop into IceCube (project) Links to project office, Budget and reporting procsess Crosslinks to DAQ, Monitoring, Calibration, Detector Verification, Simulations, Deployment & Logistics –“Preliminary” IceTop Design Document ftp://ftp.bartol.udel.edu/seckel/icetop/idd/idd_6_2.pdf –Integration into IceCube DAQ System Design Several meetings DAQ Software Design Document (Apr) –IceTop specific engineering Tank systems under development Many discussions w/LBNL System Design Document (May)

IceTop Status: 11 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Tanks “Clear” Ice Instrumented with PMTs Minimum maintenance Practical deployment effort Logistics considerations HGLG

IceTop Status: 12 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Requirements Integrated deployment –Power and Data during deployment (45 days) Optical quality –Mean free path > 1 m (except near bottom & walls) –Photon lifetime < 15 ns –Quantum efficiency > per High Gain DOM Insulated on top and side (bottom TBD) –Tanks stable for 10 yrs –DOM thermal control

IceTop Status: 13 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Deployment Freeze in situ vs Tank Factory Time Line Sequence –Trench –Prepare site –Prep 1 –Position tank –Prep 2 –Fill –Freeze –Close up and commissioning Jan 31

IceTop Status: 14 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Tale of Two Techniques Freeze from top, down Cold open top Insulate bottom Insulate side (TBD) Active de-gas w/circulation Mixing: buoyancy Finish at bottom Top Down (Lake) Freeze from bottom, up Warm closed top Insulate side (TBD) Cold bottom w/air circulation Vigorous water circulation scrubs bubbles from ice/water interface Finish at top Bottom Up (Ice sculpture) Main Heat Loss ice water 2 nd heat loss drives convection de-gas system Main Heat Loss ice water pump Air bubbles released from surface Warm Air Cold Air Insulation

IceTop Status: 15 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Top Down: de-gas lab test

IceTop Status: 16 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA System Components for POW test De-gasser Dissolved Oxygen Sensor Insulation Main Circulating Pump Inlet Temperature Control Temperature Sensors Ice Quality Monitors

IceTop Status: 17 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Bad News and Good News Bad: Component failure let large air bubbles in when freeze was 2/3 complete. Good: You are viewing the bubbles through two feet of ice! The ice can be healed

IceTop Status: 18 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Put pole prototype in place

IceTop Status: 19 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA End of top down freeze eye chart

IceTop Status: 20 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Top down models POW Mixing tests N O

IceTop Status: 21 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Top down polar models Varying surface temp (-20, -40) N O Varying # of de-gas channels (2, 10)

IceTop Status: 22 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Test tanks at Port of Wilmington Top-down tankBottom-up tank (with two rows of insulation remaining)

IceTop Status: 23 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Lab tests: bottom-up

IceTop Status: 24 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Depth profile of bottom-up tank Andrew McDermott measuring ice thickness in bottom-up tank --pump is on the right of the photo

IceTop Status: 25 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 26 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Summary of IceTank production Deployment plan taking shape Requirements for optical quality being developed in conjunction with simulations Two basic tank-freezing methods studied –Top down: Further along in engineering (3 rd generation). Appears to be feasible. –Bottom up: data from POW test not fully analyzed. 1 st generation of engineering development.

IceTop Status: 27 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 28 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 29 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 30 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Muon signals Four locations of muon telescope: Setting 2: some trajectories go through OM Setting 1: diagonal trajectory deposits more energy Setting 3: opposite pump Setting 4: near pump

IceTop Status: 31 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 32 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA

IceTop Status: 33 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Sim: Conclusions

IceTop Status: 34 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Muon Measurement at Zenith=82º and 85º X. Bai 07-Mar-2003 Bartol Research Institute University of Delaware Newark, DE 19716

IceTop Status: 35 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Detector setup Oblique muons Snow surface S1 S2 V-s1V-s2 Vertical muon 401.3’’ 789.8’’ 55.5’’ 67.0’’ 2001 tank Air Shower Front 2001 Tank and scintillators to catch muon s: Scintillate for anti-coincidence ( V-s2 and V-s1) Scintillate for coincidence trigger (S1 and S2)

IceTop Status: 36 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Muon Fluxes at θ=82.13º and 85.15º θ=82º θ=85º Scint. separation 30.5 ns 63.5 ns E muon ( > MeV ) Scint size 0.2 m m 2 N of events(3 cuts) Time (in day) Dead time 15% 15% flux (cm -2 sr -1 s -1 ) 1.60× ×10 -5 Statistical error ± 8.5% ± 21.3% System error (cut parameters) -25.6% +17.5% -40.7% +33.3% Other errors (position survey,...) (±7%) (±7%) flux (cm -2 sr -1 s -1 ) ( ± 0.25)×10 -4 ( ± 2.68)× data: zenith: θ=0º θ=15º θ=35º E muon ( > MeV ) Flux ( cm -2 sr -1 s -1 ) 1.82× × × orders change

IceTop Status: 37 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA PY2 - plans IceTop design and integration –Integrate IceTop engineering into IceCube project –Finish design of firmware for IceTop DOMs –Produce IceTop DAQ –Full integration into IceCube DAQ Deploy 2 test-tanks at Pole –in situ test of freezing method(s) –Study water supply: quality, quantity –Study implications for deployment DAQ & DOM software, firmware Simulation studies –Full-scale shower simulations –Trigger rates for various classes of events –Assessment of veto efficiency

IceTop Status: 38 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Project Year 2-Milestones Preliminary design review 7/15/03 Tanks etc at Port Hueneme 9/30/03 DAQ modifications 11/15/03 Critical design review 2/15/04

IceTop Status: 39 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Summary Progress PY-1 –Design –Tanks –Simulations Horizontal muon flux measurement Plans for PY-2

IceTop Status: 40 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA STOP This slide intentionally left blank.

IceTop Status: 41 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Shower Rates IceTop Triggers –E s > 300 TeV –Rate ~ 5-10 Hz Veto for InIce m –E s ~ 3-30 TeV –R s ~ 30 KHz –R sta. ~ 20 Hz –InIce R m ~ 1500 Hz Veto for m bundle –E s > 30 TeV –Rate ~ 500 Hz dE/dX Coincident Geometry Shower s s InIce

IceTop Status: 42 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Single particle rates per tank Single Muons 1200/second Vertical m- flux measured at SP with m telescope Tank rate inferred from geometry Soft Component (>30 MeV) 1000/second e - (E>0): SPASE D1 trigger (scintillator) – m correction Spectrum + composition (e, g) from shower sim Check – Daniels and Stevens

IceTop Status: 43 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Detection requirements: regular showers Station efficiency 5% at 3 TeV: A eff (10 TeV) = 6000 m 2 Background rejection for veto work: local coincidence at station Peripheral detection: SPE resolution desired Resolve core of EeV shower at 100 m: 10 5 pe/10 ns Dynamic range > VE m 0.1 VE m 100 TeV 10 PeV 1 EeV

IceTop Status: 44 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Horizontal Showers + UHE n m detection  Incident cosmic-ray nucleus Penetrating muon bundle in shower core Coincidence window t = 5 m s. 160 tanks at ~ 2 KHz, dt = 3 m s Veto requires 6 m within 5 microseconds across the array. The right target/absorber – 90 < q z < 180 Too thick – 0 < q z < 60 Too thin – 60 < q z < 90 Just right Incident n m UHE muon

IceTop Status: 45 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Additional Requirements Air shower reconstruction –Pulse timing to 5 ns dq ~1 ° –Size fluctuations E s, (x,y) Communication bandwidth –DOM :: DOM HUB 100 KBps (raw hits) –Satellite0.5 GB/day (filtered data) Additional Constraints

IceTop Status: 46 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Data Return Strategy Singles (Muons + E e > 30 MeV) –id (2), time (4), fit parameters(6) – 12 bytes –2500 Hz * 12 B = 30 KBps/DOM Soft Component –Check for local coincidence (two tanks) –R showers ~ Hz –R uncorrelated coincidence ~ Hz –Mostly simple fits – 2 KBps/DOM Waveform –5% simple fit fails ~ 100 Hz –Scaled selection of minimum bias and event triggers ~ 10 Hz –Compress and return complete waveform ~ 100 B –200 Hz * 100 B = 20 KBps/DOM Separation & Threshold Threshold

IceTop Status: 47 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Design Summary Science goals –veto, calibration, cos-ray science Air shower events –large (trigger), small (data access), vertical + horizontal Detection requirements –threshold, dynamic range, background rejection, reconstruction Constraints –bandwidth (DOM hub, satellite) Detector requirements –local coincidence, time resolution, feature extraction Design –2 tanks –2 DOMs with special FPGA logic –data buffered for 10 sec at DAQ

IceTop Status: 48 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Stop

IceTop Status: 49 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Efficiency

IceTop Status: 50 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA Apply Geometry Filter ? Vert Shower Triggers Merge data into time ordered list Global Trigger Extract complete sublist for  t Scan sublist for coincidence Station hits Forward Trigger Reports for  t For horiz. showers, change Station hits to Tank hits Generate Trigger Report

IceTop Status: 51 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop DOM Strategy Start Feature Extraction FX Ok ? Id = Shower, Features Id = ?, Waveform Local Coincidence ? No Start local coincidence Muon Amplitude ? Bit Bucket Id = Muon, Features No Yes DOM Activity Trigger FX Ok ? Id = Shower, Waveform No Yes

IceTop Status: 52 David Seckel – 3/30/2003 Laguna Beach Berkeley, CA IceTop Data Handler Vertical Shower Trigger Time Correction Common Event Builder Global Trigger Hubs Separate Monitor Data Create stream for “station hits” Create stream for “tank hits” IceTop Data Buffer Post trigger data retrieval Monitoring Online In-Ice Trigger Horiz. Shower Trigger Trap calibration data