The TAIGA experiment: from cosmic ray to gamma-ray astronomy in the Tunka valley. N.Budnev, Irkutsk State University for the TAIGA - collaboration

Transcription

1 The TAIGA experiment: from cosmic ray to gamma-ray astronomy in the Tunka valley. N.Budnev, Irkutsk State University for the TAIGA - collaboration

2 TAIGA collaboration S.F. Berezhnev 1, N.M. Budnev 2, M. Büker 6, M. Brückner 8, A. Chiavassa 4, A.V.Gafarov 2, O.B. Chvalaev 2, O.A. Gress 2, T.I.Gress 2, A.N. Dyachok 2, S.N. Epimakhov 6, U. Einhaus 6, D. Hampf 6, R. Hiller 5, D. Horns 6, A. Haungs 5, A.L. Ivanova 2, N.I. Karpov 1, N.N. Kalmykov 1, Y.A. Kazarina 2, N.V.Kirichkov 2, S.N.Kiryuhin 2, M. Kleifges 5, E.N. Konstantinov 2, E.E. Korosteleva 1, D.G.Kostunin 5, V.A. Kozhin 1, O Krömer 5, M. Kunnas 6, L.A. Kuzmichev 2,1, V.V.Lenok 2, B.K. Lubsandorzhiev 3, N.B. Lubsandorzhiev 1, R.R. Mirgazov 2, R.Mirzoyan 9,2, R.D.Monkhoev 2, R. Nachtigall 6, A.L. Pakhorukov 2, M.I. Panasyuk 1, L.V. Pankov 2, V.A. Poleschuk 2, E.G. Popova 1, A.Porelli 8, V.V. Prosin 1, V.S. Ptuskin 7, G.I. Rubtsov 3, C. Rühle 5, V.S. Samoliga 2, P.S. Satunin 7, Yu.A. Semeney 2, B.A. Shaibonov(junior) 3, A.A. Silaev 1, A.A. Silaev (junior) 1, A.V. Skurikhin 1, C. Spiering 8, F. Schröder 5, L.G. Sveshnikova 1, M. Tluczykont 6, R. Wischnewski 8, A.V. Zagorodnikov 2, V.L.Zurbanov 2 1 Skobeltsyn Institute of Nuclear Physics MSU, Moscow, Russia 2 Institute of Applied Physics ISU, Irkutsk, Russia 3 Institute for Nuclear Research of RAN, Moscow, Russia 4 Dipartimento di Fisica Generale Universiteta di Torino and INFN, Torino, Italy 5 Institute of Technology, Karlsruhe, Germany 6 Institut fur Experimentalphysik, University of Hamburg, Germany 7 IZMIRAN, Troitsk, Moscow Region, Russia 8 DESY, Zeuthen, Germany 9 Max-Planck-Institute for Physics, Munich, Germany

3 Motivation for TAIGA Tunka Advanced Instrument for cosmic rays and Gamma Astronomy 162 high energy gamma- sources was discovered with IACT arrays But no gamma- quantum with energy more then 50 TeV were detected up to now. An array with area > 1 km 2 is required

4 HiSCORE: (Hundred*i Square-km Cosmic Origin Explorer) Large instrumented area: km 2 - low flux sensitivity Large station area: 0.5-1m 2 - photons far off-axis Wide station spacing: m - low cost; reconstr. lever-arm Fast electronics: photon arrival times for X max and direction Ground based array of detector stations

5 Tunka-133 array: 175 optical detectors distributed on 3 km 2 area 1 км 50 km from Lake Baikal

6 The main Tunka-133 results Details in V. Prosin s talk, this conference First knee Second knee. All particles energy spectrum I(E) E 3 Mean logarithm of primary mass. 1. Good accuracy positioning EAS core (5-10 m) 2. Good angular resolution ~ deg 3. Good energy resolution (~ 15%, in principal up to - 5% ) 4. Good accuracy of primary particle mass identification: accuracy of Xmax measurement ~ g/cm 2

7 Towards Very High Energy Gamma-Ray Astronomy array at Tunka Valley TAIGA Tunka Advanced Instrument for cosmic rays and Gamma Astronomy 5 arrays = + Tunka-133 Tunka-Rex Tunka-HiSCORE array -net of non imaging wide-angle optical stations Shower front and LDF sampling technique for core position and energy reconstruction. Angular resolution 0.1 deg, Xmax measurement for hadron rejection. Tunka-IACT array -net of Imaging Atmospheric Cherenkov Telescopes with mirrors - 4 m diameter about and cheap matrix of PMTs charged particle rejection using imaging technique. Tunka Grande array net of scintillation detectors, including underground muon Detectors with area m 2 area charged particle rejection.

8 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. Main Topics for TAIGA Charged cosmic ray physics Energy spectrum and mass composition anisotropies from to10 18 ev events (in 1 km 2 array) with energy > ev Particle physics Axion/photon conversion. Hidden photon/photon oscillations. Lorentz invariance violation. pp cross-section measurement. Quark-gluon plasma. TAIGA energy range For γ and CR

9 Tunka - HiSCORE. Non-imaging air Cherenkov array Angular resolution : ~ 0.1 degree Large Field of view (FOV): ~ 0.6 sr Area: from 1 km km 2 Spacing between Cherenkov stations m ~200 channels / km 2. Total cost ~ 5 millions Euro (for 10 km²) 50 millions Euro (for 100 km²) Wide-angle time-amlitude sampling Cherenkov Technique is very promising way to study high energy gamma-rays.

10 Tunka-HiSCORE electronic box DRSboard 0.5 ns step Connector for WR- board

11 White Rabbit (WR) timing system A distributed DAQ system for the Tunka-HiSCOREbased on the White Rabbit (WR) timing system has been developed in order to achieve a sub-ns time resolution WR main structure WR main components

12 EAS shower reconstruction with WR timing system data Arrival time delay vs distance R from the shower axis for an event. Red line: reconstructed shower profile. Distribution of fit residuals after shower reconstruction. Black dots: data; Red line: simulated events; Blue line: gaussian data fit.

13 Tunka-HiSCORE 2014 year setup 28 optical stations (S=0.25 km 2) Cherenkov detectors of the Tunka-133 array

14 The accuracy of EAS axis direction reconstruction The RMS=1.1 ns for Tunka-HiSCORE provides an accuracy of an γ and CR arrival direction about 0.1 degree

15 The amplitude spectrum of PMTs pulses of a Tunka-HiSCORE optical station NSB Counting rate = Hz Threshold Cherenkov photons flux: ph / cm 2 Threshold (120 photoelectrons)

16 LDF of Cherenkov light from gamma-rays induced EAS and threshold distance from core 1 Threshold Cherenkov photons flux: ph / cm 2 E γ = 30 TeV 2 Eγ = 100 TeV 100 TeV 30 TeV 120 m 230 m distains from core Threshold distance from core 100 TeV 30 TeV

17 year data single Cherenkov light pulses >4 stations coincidence ~50,738 events >9 stations coincidence 2000 events Amplitude distance function Reconstructed core position for an event, the area of the circles is proportional to loga, with A the station signal amplitude Arrival time delay vs distance R from EAS core

18 First Tunka-HiSCORE spectrum All particles spectrum Spectrum structure the knee around

19 Tunka-HiSCORE 2015 year setup 4 Optical stations with high sensitivity 10 inch PMT R7081

20 The Tunka Grande scintillation array Permanent absolute energy calibration of Cherenkov arrays Tunka-133 and Tunka-HiSCORE. Round-the-clock duty cycle; Trigger for radio array Tunka-Rex Improvement of mass composition data Rejection of p-n background 200 γ EAS, θ = 40 o E 0 = ev 150 N, events γ EAS, θ = 0 o p EAS, θ = 40 o p EAS, θ = 0 o N Underground Muon detector Surface Electron detector

21 228 KASCADE-Grande scintillation counters ( 0.64 m 2 ) in 19 stations of the surface detector 152 KASCADE-Grande scintillation counters in underground containers Entrance to muon detector Future plan: 2000 m 2 muon detectors Electronic box

22 Tunka-Grande Data Acquisition System

23 EAS radio signal detection in the TAIGA project Promising novel technique to detect Cosmic Rays: - Energy, direction, particle type - low-cost, high duty-cycle At present time achieved precision of the EAS energy measurement with Tunka radio array Tunka-Rex - 15% about and a precision of depth of the EAS maximum (Xmax) measurement better then 40 g/cm 2. Tunka-Rex - a radio detector for cosmic-ray and gamma air showers, triggered by Tunka-133, Tunka-HiSCORE and Tunka-Grande. Geomagnetic effect: deflection of e + e -, time-varying transverse current Askaryan effect, time-varying net charge ( 10% contribution)

24 Tunka-Rex (Tunka Radio Extention) array Layout of Tunka-133 and Tunka-Rex (2015 y setup - 44 SALLA ) 25 antenna stations triggered by Tunka antenna stations triggered by Tunka-Grande The gain G over zenith angle at 50MHz of the SALLA for dierent ground conditions.

25 The correlation of reconstructed radio and Cherenkov distance to shower maximum (g/cm 2 ) The correlation of reconstructed radio and Cherenkov energy

26 Tunka IACT array consisting of TAIGA A system of 16 IACT (Imaging Atmospheric Cherenkov Telescopes) operating together with TUNKA-133, Tunka-Rex, Tunka-HiSCORE and Tunka-Grande. Mirror diameter m (34 mirrors with 60 cm diameters), 4.8 m focal distance Spacing m Covering an area of 1 km x 1 km An energy range - TeV-EeV Threshold energy ~ 2-3 TeV Field of imaging cameras view of 10 x 10 Pixel size -0.4, Low cost Camera : 570 PMTs ( XP 1911) with 15 mm useful diameter of photocathode Winston cone: 30 mm input size, 15 output size 1 single pixel = 0.36 deg full angular size 10.3 deg DAQ - MAROC3

27 Imaging + non-imaging techniques Tunka- HiSCORE: core position, direction and energy Tunka-IACT : gamma/ hadron separation (monoscopic operation)

28 HEGRA like telescope Now in production in JINR (Dubna)

29 Conceptual design of the TAIGA-IACT IACT camera mechanics Outside case Camera opening lid Ventil for volume ventilation MAROC-3 based Trigger, DAQ & Slow Control System Power supplies, could be set outside camera, in a separate box Plexiglas window, sealed system Light guides PMT-modules PCB HV system Connections T and pressure control, forced ventilation system 29

30 Camera of the telescope 950 mm PMT Maroc-3 64 channel board Cluster 28 PMTs

31 Schematic of MAROC 3 board Slow control H / V 24V 12V L / V USB PMT PMT ASIC MAROC 3 Ch trg 1 32 Config Data FPGA Board trg Hold Data pulse ADC Osc 40МГц current ADC Slow control Matching on the single PMT anode output with MAROC Up to 32 PMT Dead time for ADC data 200 microsec Slow control of PMT current and H/V

32 Very near future of Tunka experiment November of 2015 y: 1. Tunka Cherenkov detectors with single PMT of Ø 20 cm 2. Tunka-HiSCORE 32 Low threshold Optical stations with PMT. 3. Tunka-Grande 19 scintillation stations with surface and underground detectors. 1. Tunka-Rex 44 radio antennas 2. Tunka- IACT Prototype of the first Tunka IACT with mirror of 15 m 2 area

33 Gamma- obervatory TAIGA (Stage 2) ( years): 104 Tunka-HiSCORE optical ctations + 9 imaging telescopes (IACT) m 2 muon detectors + 40 Tunka- HiSCORE stations with 10 PMT R Tunka- HiSCORE stations with 8 PMT 9 Tunka- IACT with mirror 4.5 m diameter

34 Sensitivity for gamma rays Tunka HiSCORE 64 stations with 150 m spacing (50 events 500 hours) Tunka HiSCORE + 5 IACT-telescopes ( very preliminary)

35 Summary and outlook 1. The Cherenkov technique is a very suitable way to study high energy cosmic rays as well gamma-rays. the Tunka valley is one of the best places for construction of a large Cherenkov arrays. 2. The structure of the CR energy spectrum in the energy range of to ev was measured with high resolution. The second knee at energy ~ ev points to a transition from Galactic to extragalactic sources of CR. 3. The new gamma observatory TAIGA will allow: - To perform search for local Galactic sources of gamma-quanta with energies more than TeV (search for PeV-trons) and study gamma-radiation fluxes in the energy region higher than TeV at a record level of sensitivity. - To study energy spectrum and mass composition of cosmic rays in the energy range of ev at an unprecedented level of statistics. - To study the high energy part of the gamma-ray energy spectrum from the most bright blazars (absorption of gamma-quanta by intergalactic phone, search for axion-photon transition).

36 Thank you for attention!