Tunka-133: status and results L.A.Kuzmichev (SINP MSU) On behalf on the Tunka Collaboration Moscow, May 2011

S.F.Beregnev, S.N.Epimakhov, N.N. Kalmykov, N.I.KarpovE.E. Korosteleva, V.A. Kozhin, L.A. Kuzmichev, M.I. Panasyuk, E.G.Popova, V.V. Prosin, A.A. Silaev, A.A. Silaev(ju), A.V. Skurikhin, L.G.Sveshnikova I.V. Yashin, – Skobeltsyn Institute of Nucl. Phys. of Moscow State University, Moscow, Russia; N.M. Budnev, A.V.Diajok, O.A. Chvalaev, O.A. Gress, A.V.Dyachok, E.N.Konstantinov, A.V.Korobchebko, R.R. Mirgazov, L.V. Pan ’ kov, Yu.A. Semeney, A.V. Zagorodnikov – Institute of Applied Phys. of Irkutsk State University, Irkutsk, Russia; B.K. Lubsandorzhiev, B.A. Shaibonov(ju), N.B. Lubsandorzhiev – Institute for Nucl. Res. of Russian Academy of Sciences, Moscow, Russia; V.S. Ptuskin – IZMIRAN, Troitsk, Moscow Region, Russia; Ch. Spiering, R. Wischnewski – DESY-Zeuthen, Zeuthen, Germany; A.Chiavassa – Dip. di Fisica Generale Universita' di Torino and INFN, Torino, Italy. D. Besson, J. Snyder, M. Stockham Department of Physics and Astronomy, University of Kansas, USA Tunka Collaboration

Search for the Acceleration Limit of Galactic Sources - Energy range eV demands: - 1 km² with spacing smaller than that at Auger - complementary techniques IceTop IceCube - KASCADE-Grande terminated - IceTop/IceCube in operation - Tunka-133 (calorimetric) in operation - NEVOD-DÉCOR in operation -GAMMA in operation - Auger low energy extension 80% ready - HiSCORE planned -LHAASO planned

V.Ptuskin and V.Zirakashvili,2010 Tunka-133

OUTLINE 1. Non-imaging Air Cherenkov Technique 2. Tunka-133: construction and deployment. 3. Results after first season. 4. Plan for the Tunka-133 upgrading. 5. Future plans.

20-30km P, A For E e >25 MeV V e > C/ n – light velocity in air Cherenkov light Photons detectors Q tot   N(x) dx ~ E Atmosphere as a huge calorimeter E (PeV) = 0.4 Q(175) ph· ev -1 cm -2 Lateral Distribution Function

Advantage of Cherenkov Technique: 1. Good energy resolution - up to 15% 2. Good accuracy of X max g/cm 2 3. Good angular resolution – 0.3 deg 4. Low cost – Tunka-133 – 1 km 2 array: E ( construction and deployment) E( PMTs) Cost of 100 km 2 array E Disadvantage: 1.Small time of operation ( moonless, cloudless nights) – 5-10% 2. Existence of moving lids on modules

Summary of methodic used in Tunka-133 ( more detail in V.Prosin report at Wednesday ) 1. Energy: E (PeV) = 0.4 Q(175) ph· ev -1 cm -2 From CORSIKA, no dependence from hadronic model 2. Core location: LFD and WDF ( width-distance function) accuracy – 10 m 3. Energy resolution: 15% 4.Xmax - p (steepness from LDF) - τ(400) – time width at 400 m from the core

Tunka-133 – 1 km 2 “dense” EAS Cherenkov light array Energy threshold eV Accuracy: core location ~ 10 m energy resolution ~ 15%  X max < 25 g∙cm -2

Tunka-133: 19 clusters, 7 detectors in each cluster Optical cable Cluster Electronic box DAQ center PMT EMI 9350 Ø 20 cm 4 channel FADC boards 200 MHz, 12 bit

Array depoliment Optical cables Detectors Testing PMTs

DAQ system Cluster Local trigger: > 3 hit detectors in 0.5 µs Optical detector Cluster Electronic box 1 Gb Ethernet: Data transmission + Synchronization

Optical detector of Tunka-133 PMT EMI 9350 Ø 20 cm Angular sensitivity

4 channel FADC 1. ADC AD9430, 12 bit, 200 MHz 2. FPGA XILINX Spartan-3 Port for FADC connection (trigger, requests) Optical transceiver (central DAQ connection

Time synchronization chain Accuracy of time synchronization 10 ns

Two seasons of array operation :286 hours of good weather – 2011: 270 hours of good weather. > 4  10 6 events with energy  эВ. Trigger counting rate during one night. Distribution of the number of hitted clusters in one event.  50 detectors  eV  10 events during every night with number of hitted detectors more than 100.

Experiment: Every event = 3 – 133 pair pulses: Reconstruction of parameters: 1) Delay at the level 0.25A max, 2) the full area under pulse, 3) FWHM anode dynode titi FWHM 11 th cluster 19 th cluster  500 m

EAS zenith angular distribution (E 0 >10 16 eV)

Energy spectrum (from first season data) Core position inside circle: R = 450 m Zenith angle < 45° All: >10 16 eV : > eV: 202

Example of event Energy: 2.0  eV zenith angle : 12.6 ° 125 detectors R  lg ( I light ) Core position: LDF -method WDF -method

.A– Fitting experimental points with LDF B – Fitting of  ( R) with Width – Distance Function. A B Thershold Lg Q exp (R ) LDF WDF Lg  (R )

Events with largest energy – near to eV – was found out with the help of radio antenna

182 event 353 g1 g2 Combined spectrum Tunka 25( ) plus Tunka 133 ( ) g1 = 3.2 g2 = 3.0 December 2010

202 event 373 g1 g2 Combined spectrum Tunka 25( ) plus Tunka 133 ( ) g1 = 3.2 g2 = 3.0 May 2011

353 events 277 Good pointing for the existing of “ bump” 4.2  December 2010

 MAY 2011

Specter with 2 types of sources Eknee =4 PeV (0.75)+4x150 PeV (0.25

Specter with 2 types of sources Eknee =4 PeV (0.75)+4x150 PeV (0.25) Here we need to know Meta-Galactic P He C,O Fe Si Total all –particle spectrum in our model Galactic sources

Mass composition: 3 dif. variants 1) Emax (P) In Galaxy ; 4 PeV 2) Emax (P)=4 and 600 PeV This variant predicts a heavy composition at eV 3) SNR Ia + He stars +MetaGalactic with mixed composition in sources

Plan for Tunka-133 upgrading -Far distant clusters for increasing effective area -Net of radioantennas -Low threshold array - Scintillation muon counters E 0, X max ( from Tunka-133 ), N µ

1 km. 6 additional clusters ( 42 detectors) Increasing Effective Area in 4 times for energy more than eV In operation Statistics in 2012 ( > eV) : 600 (inner events) (out events) All: 1200 events

Registration of radio signals from EAS Antennas are connected to the free FADC channels of Tunka-133 cluster electronics Choosing the type of antennas: Now 2 types of antennas were installed at Tunka Array Log-periodic antenna (D. Besson et al. University of Kansas, USA) Short Aperiodic Loaded Loop Antenna (SALLA) (A.Haungs et al. Institute fur Kernphysick, Forschungszentrum, Karslruhe, Germany 6 antennas 2 antennas Nearly 100 candidates

SCORE project – wide-angle gamma-telescope with area km 2 and threshold  30 тэВ (M.Tluczykont et al, ArXiv: ) SCORE: Study for Cosmic ORigin Explorer Time schedule 1.First SCORE Station will be installed at Tunka in this summer-autumn 2.20 station at 2012 – 1 sq. km telescope ( good chance) 3. ?? Energy spectrum from eV - compare with Tunka-25 and Tunka-133 results

Muon detectores lgNµ (corr)= lgNµ X max S = 5 m 2 40 muon detectors on the area of 1km 2

766 г/см г/см 2 Search for diffuse gamma radiation at high energy

Future plan: 100 km 2 array 1.Spacing between detectors – 250 m 2.Cluster principle of organization: 8-10 detector in one cluster 3. PMT - with 20 cm diameter photocathode 4. Energy threshold (3-5) eV 5. Digitization of signals in optical detectors 6. Optical cables for data transmission and synchronization PMT pieces Cable – 1000 km Total price Eu Time schedule 1. Proposal to the end of When - ? 3. Where ?? May be with Auger-Next

Conclusion 1.The spectrum from to eV cannot be fitted with one power law index g : 3.2 to 3.0 at eV. 2. Very good agreement with KASKADE-Grande results ( up to 7  ). 3. For energy > eV we need much more statistics. 4. “Bump” at eV - possible indication of a bump + agreement with GAMMA. But not seen by KASKADE-Grande. 5. Indication on light composition at energy > eV 6.Update 2011: - Far distant clusters. - Net of radio antennas. - First SCORE detectors.

Thank You