1. Experiment Tunka : High energy cosmic rays and Gamma-ray astronomy
L.A.Kuzmichev (MSU SINP)
on behalf of Tunka Collaboration
Napoli 2013

2. Tunka Collaboration
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, O.A. Chvalaev, O.A. Gress, A.V.Dyachok, E.N.Konstantinov, A.V.Korobchebko,
R.R. Mirgazov, L.V. Pan’kov, A.L.Pahorukov, 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 Universita' di Torino and INFN, Torino, Italy.
A.Haungs, F. Schroeder, R.Hiller
Karlsruhe Institute of Technology, Karlsruhe, Germany
D.Horns, M.Tlucziykont , R.Nachtigall, M.Kunnas
Hamburg University, Germany

3. OUTLINE 1. Tunka-133. 2. Energy spectrum. 3. Mass composition
4. Plan for the Tunka-133 upgrading.
5. Low energy extension : Tunka-HiSCORE project.

4. Accuracy: core location ~ 10 m energy resolution ~ 15%
1 km
Tunka-133 EAS Cherenkov array –
175 optical detectors on the 3 km2
Energy threshold ~ 1015 eV
Accuracy: core location ~ 10 m
energy resolution ~ 15%
 Xmax < 25 g∙cm-2

5. Scientific aims Search for Acceleration Limit of Galactic Sources
( transition from galactic to extragalactic CR)
Study of a new methods of EAS registration
Low energy extension: Multi-TeV gamma-ray astronomy and CR in energy range 100 TeV - 5 PeV

6. 7 detectors in each cluster
Tunka-133: 19 clusters,
7 detectors in each cluster
Optical cable
DAQ
center
Cluster
Electronic
box
PMT
EMI 9350
Ø 20 cm
4 channel FADC boards
200 MHz, 12 bit

8. Experimental data fitted with LDF
Using of Cherenkov Light Lateral Distribution Function (LDF) for the Reconstruction of EAS Parameters
LDF from CORSIKA
Q(R) = F(R, p) (only one
parameter)
Experimental data fitted with LDF
light flux at core distance 200 m – Q200  Energy
P = Q(100)/Q(200) Xmax
steepness of LDF

9. Energy reconstruction
E = A (Q200) g
Density of Cherenkov light at core distance of 200 m
For – eV (CORSIKA):
g = 0.94±0.01

10. Absolute energy calibration : The QUEST experiment ( Cherenkov detectors at EAS-TOP)
Integral spectrum
σsys(E) = 8% p
Normalization
point for Tunka-133
P – steepness of LDF (Lateral Distribution Function)

11. Three seasons of array operation
:286 hours of good weather .
2010 – 2011: 305 hours of good weather.
2011 – 2012: 380 hours of good weather
6106 events with energy 1015 эВ.
Trigger counting rate
during one night .
50 detectors
 eV
10 events during every night with number of hitted detectors more than 100.
Distribution of the number of hitted clusters
in one event.

12. IN-events:
Core position inside
circle: R < 450m
Zenith angle < 45°
>1016 eV:
>1017 eV: 605
OUT- events:
R <800 m
> eV: 1900
800 m
450m

14. Shower front
Tns
T ns = (R+200/R0 )2 ×3.3 ns

15. WDF – width distant function
ADF
WDF
LDF
ADF – amplitude distant function is used for core location

17. 1900 events
> 1017 eV

18. Second
knee
γ~ 3.0
γ~ 3.3
~3 ·1017 eV

19. σsys(E) = 8%
At E= eV
From QUEST
experiment
σsys(E) = 15%
At eV
due to
uncertainty in g

21. Energy Spectrum

23. Mean Depth of EAS maximum Xmax g·cm-2
Mean logarithm of primary mass. PRELIMINARY

24. Conclusions
1. The spectrum in the energy range of to eV cannot be fitted with single power law index
3.21 ± (6·1015 – 2·1016 eV)
2.97 ±0.01 (2·1016 – 1017 eV)
3.30 ± 0.1 (3 ·1017 – 1018 eV)
There is an indication on the second knee at ~3·1017 eV
3. Tunka spectrum = K-Gr spectrum inside energy reconstruction systematics.
The key question – to increase accuracy of absolute energy calibration.
Is it possible to have 5% accuracy?
4. More statistics is needed at the energy range of 1017 – 1018 eV
The array will continue data taking for another 4-5 seasons.
5. Primary mass composition changes from the light (He) at the knee to the heavy at 3·1016 eV. The mass composition is heavy till at least 1017 eV. More statistics is needed in the energy range of 1017 – 1018 eV

25. Plan for upgrading Net of radio antennae Tunka-REX ( Radio Extension)
Deployment of Grande stintilator detectors
- Cross calibration of Cherenkov light and fluorescent light methods.
Low energy extension – Tunka –HiSCORE

26. Tunka :
Grande-station
( now in Moscow)
HiSCORE

27. Registration of radio signals from EAS
Short Aperiodic Loaded Loop
Antenna (SALLA)
(A.Haungs et al. Institute fur
Kernphysick, Forschungszentrum,
Karslruhe, Germany
20 antennas was installed in autumn 2012
Antennas are connected to the
free FADC channels of Tunka-133
cluster electronics

28. Absolute energy calibration experiment
Absolute energy calibration experiment. Repeating the “QUEST” at eV
Lg (Ne / E, Tev) -P
-Fe
Zenith-angle: 0º -45º
Energy: 1016 – 1017 eV
20 scintillation counters, 10 m2
2000 events with E >3·1016 eV per season p
P – steepness of LDF

29. Cross calibration of Cherenkov light and fluorescent light methods.
Image detector from TUS experiment
S= м2
Field of view
± 7 deg
7-10 km

30. A wide-angle gamma observatory
Тunka-HiSCORE
A wide-angle gamma observatory
HiSCORE stands for
Hundred*i Square-km
Cosmic Origin Explorer

31. Main Topics Gamma-ray Astronomy Charged cosmic ray physics
Gamma-ray Astronomy
Search for the PeVatrons.
VHE spectra of known sources: where do they stop?
Absorption in IRF and CMB.
Diffuse emission: Galactic plane, Local supercluster.
Charged cosmic ray physics
Energy spectrum and mass composition from 1014 to1018 eV.
108 events (in 1 km2 array) with energy > 1014 eV per one season (400 hours).
Particle physics
Axion/photon conversion.
Hidden photon/photon oscillations.
Lorentz invariance violation.
pp cross-section measurement.
Quark-gluon plasma.

32. What we can see with 1 km2 array (short list)
Name RA
degrees
Decl
Flux F at 1 TeV,
10-12cm-2 s1TeV-1 Г
Flux F at 35 TeV,
10-17cm-2 s-1TeV-1
(from Milagro)
Time of observation per one year
(х 0.5- weater factor)
Number of events per one season
E> 20 TeV
Tycho SNR
(J )
6.359
64.13
0.17 ±0.05
Г=1.95 ±0.5
236h 88
Crab
32.6 ±.9.0
Г=2.6 ±0.3
162.6 ±9.4
110h,
680
SNR IC443
(MAGIC J )
0.58 ±0.12
Г=3.1 ±0.30
28.8 ±9.5
112h,
2 –(from MAGIC)
50 ( from Milagro)
Geminga
MGRO C3
PSR
98.50
17.76
37.7 ±10.7
102h, 80
M82 (Starburst Galaxy)
148.7
69.7
0.25 ±0.12
Г=2.5 ±0.6±0.2
325h, 22
Mkn 421 (BL, z=0.031
Variable )
50-200 Г=
140h
SNR
(J )
337.26
61.34
1.42 ±0.33 ±0.41
Г=2.29 ±0.33 ±0.30
70.9 ±10.8
167h
140 ( from VERITAS
235 ( from Milagro)
Cas A (SNR, G )[6]
1.26 ±0.18
Г=2.61 ±0.24±0.2
177h 40
CTA_1(SNR,PWN)
1.5
72.8
1.3
Г=2.3
266 h
200

33. Methodical approaches for 3 stages
Shower front and LDFsampling technique (at the first stages).
Angular resolution – 0.1 deg,
Xmax measurement for hadron rejection.
Using of small mirrors net with cheap matrix of PMTs for imaging technique.
3. Using of large area muon detectors for hadron rejection.

34. Tunka-HiSCORE – 1 km2 stage 1
9352KB
8’’, ET

35. Tunka-HiSCORE – 1km2 stage 2
12’’
Hamamatsu
300 m
2 m 2 mirror,
±7º FOV,
No image

36. Tunka-HiSCORE – 1km2 stage 3
12’’
Hamamatsu
300 m
Installing of
PMTs matrix,
Image techniques
2 m 2 mirror,
±7º FOV,

37. After October 2012: 3 optical stations for common operation with Tunka-133

38. 200 m
New station
150 m

39. Calibration
light source
4 PMTs
Station Electronics

40. Thank you

41. all-particle spectrum and composition of cosmic rays
<lnA> based on <Xmax>; data from Hoerandel 2007