1. A new 1 km2 EAS Cherenkov Array in the Tunka Valley
B.K.Lubsandorzhiev for TUNKA Collaboration
Institute for Nuclear Research of RAS, Moscow Russia
and
Kepler Center for Astro and Particle Physics
University of Tuebingen, Germany

2. Georgiy Timofeevitch Zatsepin–

3. EAS Cherenkov Experiment in the Tunka Valley
Location: Tunka Region, Republic Buryatiya, Siberia, Russia
Start of the experiment: 1994

4. S. F. Berezhnev, N. N. Kalmykov, E. E. Korosteleva, V. A. Kozhin, L. A
S.F. Berezhnev, N.N. Kalmykov, E.E. Korosteleva, V.A. Kozhin, L.A. Kuzmichev, M.I. Panasyuk, V.V. Prosin, A.A. Silaev, A.A. Silaev(ju), A.V. Skurikhin, I.V. Yashin, A.V. Zablotsky – Skobeltsyn Institute of Nucl. Phys. of Moscow State University, Moscow,
N.M. Budnev, O.A. Chvalaev, O.A. Gress, A.V. Kochanov, 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)
– Institute for Nucl. Res. of the Russian Academy of Sciences, Moscow, Russia;
V.S. Ptuskin
– IZMIRAN, Troitsk, Moscow Region, Russia;
Ch. Spiering, R. Wischnewski
– DESY-Zeuthen, Zeuthen, Germany;
G. Navarra , 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

5. ? P (E) = AE – (  +1) Extragalactic CR P (E)  E 3 AGNs
SN shells – Galactic CR
New sources or
Transition to
Extragalactic CR

6. Tunka -25
S ~ 0.1 km2
Eth ~ 0.8 PeV
 ~ 0.5
25 hybrid phototubes Quasar-370G ( 37cm)
CR energy spectrum and mass composition
around the “knee” (~31015 eV)

7. Results of Tunka -25 CR energy spectrum CR mass composition
Lack of data in the range of 10171018 eV
Larger array is necessary to study CR with E >1016 eV

8. Tunka-133 Studies of CR in the energy range of 10151018 eV, including
the energy region where a transition from Galactic CR to
Extragalactic CR probably takes place.
KASCADE –GRANDE terminated
IceTop half ready
Auger (low energy)
TUNKA running since October 2009

9. Tunka-133 : 1 km2 “dense”, wideangle EAS Cherenkov Array
Angular aperture (S•Ω) 30 times more than for Tunka-25.
High accuracy of EAS parameters reconstruction
New method of EAS core location by measuring EAS
Cherenkov pulses waveform (signal waveforms are registered for each individual detector of the array)
Possibilities to increase the array’s effective area for
high energies by a factor of 5-10
Further developments – detection of EAS radio emission
and electromagnetic component (electrons and muons)
Registration of EAS Cherenkov pulse waveform by each detector

10. Optical detector 8 inch EMI9350 PMT from MACRO
A/D=30, high linearity (>105 pe)
Fast LED driver with high dynamic range

11. Tunka-133: 133 optical detectors (OD) grouped into 19 clusters with 7 ODs in each cluster
cable
Cluster’s
electronics
DAQ Center
PMT
EMI 9350
8 inch

12. Energy threshold ~ 1015 eV
Statistics for one season (400 h):
> 3·1015 eV – 5·105 events
1017 eV – ~ 300 events
Accuracies:
EAS core location - ~ 6 м
Energy reconstruction - ~ 15%
Xmax reconstruction -  25 g∙cm-2

13. Stages of TUNKA-133 deployment
2009 – 19 clusters
2008 – 12 clusters
2007 – 4 clusters
2006 – the 1st cluster

17. 1st season: November (2009)- March (2010)
300 hours of observation.
2106 events with E >1015 eV.
10 events every night with >100 detectors
hit.
The array counting rate
for one night
50 detectors
 eV
One night of Tunka-133 operation
One season of Tunka-25 operation
The number of hit clusters distribution

18. Experiment: Each detected event 3133 pairs of pulses:
3 parameters of each pulse are registered:
Time delay at the pulse amplitude level of 0.25Amax; 2) Pulse area;
3) Pulse width (FWHM)
 500 м
Cluster #11
Cluster #19 ti
anode
FWHM
dynode

19. Event example E0 = 2.01017 эВ =12.6 ° 125 detectors are fired
R  lg ( I light )

20. threshold B A
А – Experimental points are fit by LDF (Lateral Distribution Function).
B – Pulse widths are fit by WDF (Width vs Distance Function).

21. Tunka

22. Тunka

23. Тunka

24. Тunka

25. Тunka

26. Event example Tunka

27. increased by a factor of 4 9
Deployment of several distant clusters. To calibrate shower core location method based on WDF (Width vs Distance Function)
E > 5∙1017 eV
Effective area will be
increased by a factor of 4 9
1 km
0.5 km
Tunka-133
1. 5 km

28. 31017 eV

29. Calibration of the Array
High power LED source with ~1012 photons
 1kg
~ 105 pe
( L ~ 400 m)
T ~ 3 ns nm
GPS + LED
+XBee
( radio module)
E ~1018 eV
300 – 350 м
Radio
channels
GPS

30. Plans for 2011-2012 20 sc muon detectors + net of radio antennae
DAQ center
Plans for
Cluster electronics
Optical detecor
20 sc muon
detectors +
net of radio
antennae
Scintillator muon
detectors
8-10 m2 each

31. CONCLUSION
A new 1 km2 EAS Cherenkov Array TUNKA-133 has been put
into full operation in the fall 2009.
TUNKA-133 is a powerful tool to study primary CR in the energy
range of 10151018 eV.
Studies of primary CR in this energy range will undoubtedly improve
our understanding of ultrahigh energy CR nature