Cosmic Ray Physics with Ice Top and Ice

Cosmic Ray Physics with Ice. Top and Ice. Cube Serap Tilav University of Delaware for The Ice. Cube Collaboration ISVHECRI 2010 June 28 - July 2, 2010 Fermilab 1

Ice. Cube Neutrino Observatory Neutrino Telescope & 3 D Cosmic Ray Detector Air shower detection @ 2835 m altitude (680 g/cm 2) Ice. Top Ice. Cube Ice. Top • EM component near shower max • shower size & arrival times over 1 km 2 Ice. Cube • Muonic component @ 1450 m-2450 m depth in ice • muon bundle energy over 1 km 2

Ice. Top Tank Solid block of clear ice “ Ice Cherenkov Tank” Single tank detects secondary particles in air showers : -- Me. V e± -- converting γ -- ~Ge. V μ Light yield (Cherenkov and stochastic) for each particle type is derived from a detailed GEANT 4 simulation and parameterized 3

Ice. Top Signals Ice. Cube Digital Optical Module (DOM) 2 DOMs per tank: 1 High Gain + 1 Low Gain for better dynamic range signals digitized with 3. 5 ns resolution full waveforms are transmitted 4

Tank response to VEM and calibration with Muon telescope All events Vertical muons (tagged with muon telescope ) Full Spectrum Muon Peak all particle spectrum of the DOM signals in coincidence with muon telescope Vertical Muon Peak L. Demirors et al. , ICRC 07 ar. Xiv: 0711. 0353 5

Tank response to Vertical Equivalent Muon (VEM) High. Gain DOMs continuously record single particle signals via a special calibration trigger Tank response to vertical muons is extracted weekly by a fit to the single particle spectrum 1 VEM is defined as 0. 95 x Full spectrum muon peak From MC 1 VEM ~ 3 -5 Ge. V 6

Ice. Top Station • 2 tanks per station • 1 tank hit muon, e or γ • both tanks hit air shower 7

Ice. Top Deployment 2005 -2010 2005 4 stations 2006 12 stations 2007 10 stations Ice. Top-26 2008 14 stations 2009 19 stations Ice. Top-40 Ice. Top-59 2009 14 stations Ice. Top-73 The array will be completed with 8 more stations in 2011 8

Ice. Top-26 Reconstruction Lateral shower profile at 125 m S 125 : signal at r = 125 m β : slope at r = 125 m κ = 0. 303 fixed Ø Fluctuations extracted from data S. Klepser et al. , ICRC 07 ar. Xiv: 0711. 0353 Ø Likelihood function from data & simulation -- untriggered stations are also accounted for Ø Direction reconstruction : curved shower front 9

Ice. Top-26 Resolution & Efficiency Simulations: CORSIKA with Sibyll and Fluka for 3 zenith bins [0 -30]°, [30 -40]°, [40, 46]° S 125 Eprimary derived from proton simulations for zenith range [0 -30]° Direction Core ~9 m Energy ~ 16% Effective area ~1. 5° ~ 0. 094 km 2 • requires ≥ 5 station triggers • containment criteria • quality cuts full efficiency reached > 1 Pe. V 10

Ice. Top-26 Detector Response Detector response is characterized as Response Matrix (RM) Proton Iron Primary particle Primary Energy Zenith Angle + Resolution Efficiency …. RM 11

Ice. Top-26 Energy Spectrum Unfolded Spectrum Raw Energy Spectrum Proton only Response Matrix Iron only 5 months of data 1 Jun – 31 Oct 2007 1. 1 107 events processed 4. 106 events passed F. Kislat et al. , ICRC 09 Composition sensitive zenith behavior 12

Ice. Top-40/Ice. Cube Coincident Events Data collected at 2 Hz rate Method • Reconstruct shower direction and core location with Ice. Top • fix core, improve direction using Ice. Cube reconstruction, improve core using the improved direction --- 2 iterations • Reconstruct muon bundle energy loss using charge flow information at each layer in Ice. Cube • Muon bundle energy loss is composition sensitive 13

Ice. Top-40/Ice. Cube Direction Resolution Core resolution ~ 12 -14 m Angular resolution < 1° 14

Ice. Top-40/Ice. Cube Muon Bundle Energy Loss & Composition T. Feusels et al. , ICRC 09 ar. Xiv: 0912. 4668 Data and H, Fe simulations preliminary Slant depth behavior of muon bundle energy loss Resolution, efficiency, systematics Data: 28 days Sep 2008 work in progress 15

Ice. Top-40 Near Threshold ~300 Te. V Lower the threshold below 300 Te. V for better overlap with direct measurements Restrict event selection: -- use 3 or 4 neighboring stations only -- use flat shower front -- use the same LDF -- stronger containment reconstructed core locations 16

Ice. Top-40 Proton MC Near Threshold ~300 Te. V Iron MC Increased sensitivity down to 100 Te. V for Proton showers No sensitivity to to Iron showers below 100 Te. V Ruzybayev, et all ar. Xiv: 0912. 0896 3 stations only Reconstructed energy distributions for 3 Station events. Data is consistent with Proton Showers in 100 -300 Te. V range 17

Ice. Top-59 DAQ upgrade: Single tank hits are registered (only charge and arrival times) possibility to identify single muons in tanks Station hits Single tank hits • complement the Station hits mostly at the shower outskirts • will greatly improve inclined shower reconstruction 18

Ice. Top-73 Ice. Top array is 92% complete with 73 stations out of 81 deployed Data taking started on Jun 1 2010 Differential rate of Energy proxy E* 8 or more station triggers First look at the high multiplicity data above 1 Pe. V reconstructed shower rate 1 Hz total rate = 1 Hz expect to see ~10 events per month above 300 Pe. V 19

Ice. Top-73 Finally an almost circular array Core Locations Snow build up on tanks deployed in early years affect their trigger rates and signals • Low energy electrons, gammas attenuate • Muons not affected We will account for the snow effect in our analysis 20

Ice. Top-73 183 Pe. V shower @ 50 deg High. Gain DOM near the core saturates, Low. Gain takes it over. Signals last over 3μsec 21

Ice. Top-73 Ice. Top/Ice. Cube coincident shower 293 Pe. V @5 deg 22

Summary Ice. Cube project is almost complete: 79 Ice. Cube strings + 73 Ice. Top stations • • • We have achieved good understanding of the detector -- re-working our systematics Still lack of simulation statistics due to ever changing detector size -- will get easier now as the detector is almost reached full size Enhancing our reconstruction techniques (specially for inclined showers) using detailed waveforms shapes and single tank signals 23