IceTop Design: 1 David Seckel – 3/11/2002 Berkeley, CA IceTop Overview David Seckel IceTop Group University of Delaware

IceTop Design: 2 David Seckel – 3/11/2002 Berkeley, CA ICECUBE Deep Array: InIce Surface Array: IceTop

IceTop Design: 3 David Seckel – 3/11/2002 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 Design: 4 David Seckel – 3/11/2002 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 Design: 5 David Seckel – 3/11/2002 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 Design: 6 David Seckel – 3/11/2002 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 Design: 7 David Seckel – 3/11/2002 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 Design: 8 David Seckel – 3/11/2002 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 Design: 9 David Seckel – 3/11/2002 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 Design: 10 David Seckel – 3/11/2002 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

IceTop Design: 11 David Seckel – 3/11/2002 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 Design: 12 David Seckel – 3/11/2002 Berkeley, CA HG Chan LG Chan. Tank 1 LG Chan HG Chan Tank 2 Station 1 Station 2 Station 80 DOM Hubs Data Buffers Trigger Generators Event Reconstruction Common Event Builder Global Trigger LAN InIce DATA InIce Trig.Gen. InIce Ev. Rec. LAN Data Archive LAN ICETOP DAQ

IceTop Design: 13 David Seckel – 3/11/2002 Berkeley, CA IceTop specific software DOM logic DAQ –DOM HUB –Data Buffers –Trigger logic –Filters/on-line analysis Calibration/Monitoring Simulation Analysis Simulation Chain Cosmic ray generator Air shower sim –AIRES/CORSIKA –SYBILL/QGSJet Air shower realization –Also: m ® InIce Tank response –GEANT/AUGER PMT response DOM & DAQ data flow Trigger logic Analysis

IceTop Design: 14 David Seckel – 3/11/2002 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 Design: 15 David Seckel – 3/11/2002 Berkeley, CA STOP This slide intentionally left blank.

IceTop Design: 16 David Seckel – 3/11/2002 Berkeley, CA Dataflow IceTop Hit Buffers IceTop DOM Hubs InIce String Processors IceTop Trigger(s) InIce Trigger(s) InIce DOM Hubs Event Builder Reconstruction, Archive, etc. External Trigger Global Trigger ICECUBE Data Flow