Cluster type EAS array of the NEVOD experimental complex I.A. - PowerPoint PPT Presentation

Instrumentation for Colliding Beam Physics (INSTR17) Cluster type EAS array of the NEVOD experimental complex I.A. Shulzhenko 1 , M.B. Amelchakov 1 , N.V. Ampilogov 1 , I.I. Astapov 1 , N.S. Barbashina 1 , A.G. Bogdanov 1 , A. Chiavassa 1,2,3 , D.M. Gromushkin 1 , N.N. Kamlev 1 , S.S. Khokhlov 1 , R.P. Kokoulin 1 , O.I. Likiy 1 , V.V. Ovchinnikov 1 , A.A. Petrukhin 1 , O. Saavedra 1,2 , I.I. Yashin 1 1 National Research Nuclear University MEPhI, Scientific and Educational Center NEVOD , Moscow, Russia 2 Dipartimento di Fisica dell’ Università degli Studi di Torino, Turin, Italy 3 Sezione di Torino dell’ Istituto Nazionale di Fisica Nucleare - INFN, Turin, Italy Novosibirsk, Russia, February 27 – March 3, 2017

Experimental complex NEVOD Cherenkov water detector NEVOD (volume 2000 m 3 ) spatial lattice of 91 quasi-spherical measuring modules (QSMs); 546 PMTs Coordinate-tracking detector DECOR (total area 70 m 2 ) 8 supermodules (SMs) 26 m of streamer tube chambers these chambers 9 m were used earlier in the NUSEX experiment 9 m

An example of muon bundle event detected in NEVOD-DECOR lines – reconstruction of muon tracks from DECOR data; circles – hit phototubes in Cherenkov water detector (colors reflect signal amplitudes) Local muon density in the event and EAS arrival direction are estimated from DECOR data; the energy deposit is measured in the Cherenkov water calorimeter NEVOD.

Novel approach to the analysis of data on muon bundles: method of Local Muon Density Spectra (LMDS) Description of the phenomenology of the LMDS – A.G. Bogdanov et al., Physics of Atomic Nuclei. 2010. V. 73. N 11. P. 1852 local density of EAS muons: D = m / S det (  ,  ) m – muon bundle multiplicity; S det – detector area for a given direction In an individual muon bundle event, local muon density D (at the observation point) is measured. Distribution of events in muon density D forms the LMDS. Event collection area is determined by transverse dimensions of the showers in muon component (up to several square kilometers at large zenith angles).

NEVOD-EAS array

NEVOD-EAS array Cluster DS 2 DS 1 GPS 2 1 1 2 Sync. & Control 3 4 4 3 module Counter Counter with high Communication LP dynamic unit range Central DS 3 DS 4 DAQ 3 4 4 3 post 2 1 1 2

Scintillation counter Scintillator : NE102A 80 × 80 × 4 cm 3 Photomultiplier : Philips XP3462 Most probable response to 1 particle (VEM): ~ 13 pC Upper limit of dynamic range (with standard PMT): 100 particles (VEM) Upper limit of dynamic range (with additional PMT): 10 4 particles/m 2

Detector Station (DS) 4 PMTs ( standard ): measuring EAS particle densities and time measurements . 5 th PMT (additional ): a gain of ≈ 90 times less than for the standard PMT; ensures wide linearity range of measured signals at high particle densities .

Cluster Local Post (LP) Main tasks: - summation & digitizing of PMTs signals - event selection - DS power supply - operation in exposition and monitoring modes - control of temperature inside DS and LP

Cluster Local Post (LP)

Central DAQ Post Main tasks: - cluster synchronization - cluster control - reception and storage of experimental and monitoring data

Central DAQ Post

Clusters of the NEVOD-EAS array Clusters No. 1 & 2 13.3×12.4 m 2 Cluster No. 4 15.0×15.0 m 2 Cluster No. 3 25.1×18.9 m 2

Clusters of the NEVOD-EAS array Clusters No. 1 & 2 13.3×12.4 m 2 Cluster No. 4 15.0×15.0 m 2 Cluster No. 3 25.1×18.9 m 2

Response of the NEVOD EAS DS and counters

Reconstruction of EAS arrival direction: zenith angles

Reconstruction of EAS arrival direction: azimuth angles

Example of event registered by NEVOD-EAS and NEVOD-DECOR

Conclusion In 2015–2016 , 4 first clusters (in total, 64 scintillation counters) of the NEVOD- EAS cluster type shower array located around the Experimental Complex of the CWD NEVOD and coordinate detector DECOR at the area of about 10 4 m 2 have been created and started. The distributed structure of the NEVOD-EAS array DAQ system allows to deploy registering elements of the setup even at different altitudes and provides implementation of a newly developed cluster approach to the reconstruction of EAS parameters. First test and experimental runs showed that the amplitude and temporal characteristics of responses of 4 clusters are quite similar and the detector station time resolution is about 3.7 ns . The possibility of using of cluster approach to the reconstruction of EAS parameters has been proved. In the nearest future , the NEVOD-EAS array is planned to be extended up to the area of about 2 × 10 5 m 2 .

Thank you for attention!

BACKUP: Detecting system of the CWD NEVOD 91 QSMs are arranged in 25 vertical strings (9 strings  3 QSM, 16 strings  4 QSM). Each QSM consists of 6 low-noise 12-dynode photomultipliers FEU-200 with flat 15 cm diameter photocathodes directed along rectangular coordinate axes. A wide dynamic range (1 – 10 5 photoelectrons) is provided by 2-dynode signal readout and allows to measure both high-energy cascades and energy deposit of muon bundles in the calorimeter.

BACKUP: DECOR supermodules (SMs) in the galleries around the NEVOD water tank Each SM has an effective area 8.4 m 2 and consists of 8 planes of streamer tube chambers. The length of the chambers is 3.5 m, inner tube cross section is 9×9 mm 2 . The planes of the chambers are equipped with a two-dimensional system of external readout strips.

BACKUP: Muon bundle event in the DECOR SMs multiplicity m = 144 particles, zenith angle  = 57  Run 103 --- Event 1391033 ----19-12-2015 12:53:56.18 Trigger(1-16):01110100 00010000 Weit_Time:176.034 msec 3333:0 0:3320 2939:1 Plate1:Step=25nsec 1:3221 SM=0 3121:2 2:3207 0 2988:3 3:3434 1 3705:0 0:3251 2 2985:1 1:3120 SM=1 3 3229:2 2:3313 3479:3 4 3:3427 3501:0 5 0:3187 2979:1 6 1:3045 SM=2 2887:2 7 2:3155 3127:3 3:3019 3644:0 Plate2:Step=25nsec 0:3514 3403:1 1:3103 0 3333:2 SM=3 2:3302 1 3184:3 3:3295 2 3714:0 0:3410 3371:1 3 1:3398 SM=4 3128:2 4 2:3263 3218:3 5 3:3265 3816:0 6 0:3726 3601:1 7 1:3481 SM=5 3534:2 2:3388 3765:3 3:3737 3127:0 0:3294 3373:1 1:3212 3180:2 SM=6 2:3183 2981:3 3:3184 3842:0 0:3666 3304:1 1:3437 SM=7 3229:2 2:3422 3434:3 3:3490 X-projection Y-projection