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

Cluster type EAS array of the NEVOD experimental complex

Instrumentation for Colliding Beam Physics (INSTR17) Novosibirsk, Russia, February 27 – March 3, 2017

I.A. Shulzhenko1, M.B. Amelchakov1, N.V. Ampilogov1, I.I. Astapov1, N.S. Barbashina1, A.G. Bogdanov1, A. Chiavassa1,2,3, D.M. Gromushkin1, N.N. Kamlev1, S.S. Khokhlov1, R.P. Kokoulin1, O.I. Likiy1, V.V. Ovchinnikov1, A.A. Petrukhin1, O. Saavedra1,2, I.I. Yashin1

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

Coordinate-tracking detector DECOR (total area 70 m2) Cherenkov water detector NEVOD (volume 2000 m3)

8 supermodules (SMs)

• f streamer tube chambers

spatial lattice of 91 quasi-spherical measuring modules (QSMs); 546 PMTs

Experimental complex NEVOD

9 m 9 m 26 m these chambers were used earlier in the NUSEX experiment

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.

lines – reconstruction of muon tracks from DECOR data; circles – hit phototubes in Cherenkov water detector (colors reflect signal amplitudes)

An example of muon bundle event detected in NEVOD-DECOR

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).

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 / Sdet (, )

m – muon bundle multiplicity; Sdet – detector area for a given direction

NEVOD-EAS array

NEVOD-EAS array

LP

GPS

4 3 1 2

DS 4

Counter Central DAQ post

Cluster

Counter with high dynamic range

• Sync. & Control

module Communication unit

3 4 2 1

DS 3

2 1 3 4

DS 2

1 2 4 3

DS 1

Scintillation counter

Scintillator: NE102A 80 × 80 × 4 cm3 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): 104 particles/m2

Detector Station (DS)

4 PMTs (standard): measuring EAS particle densities and time measurements. 5th 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 m2 Cluster No. 3 25.1×18.9 m2 Cluster No. 4 15.0×15.0 m2

Clusters of the NEVOD-EAS array

Clusters No. 1 & 2 13.3×12.4 m2 Cluster No. 3 25.1×18.9 m2 Cluster No. 4 15.0×15.0 m2

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 104 m2 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 × 105 m2 .

Thank you for attention!

91 QSMs are arranged in 25 vertical strings (9 strings  3 QSM, 16 strings  4 QSM). Each QSM consists

• f

6 low-noise 12-dynode photomultipliers FEU-200 with flat 15 cm diameter photocathodes directed along rectangular coordinate axes. A wide dynamic range (1 – 105 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: Detecting system of the CWD NEVOD

Each SM has an effective area 8.4 m2 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 mm2. The planes of the chambers are equipped with a two-dimensional system of external readout strips.

BACKUP: DECOR supermodules (SMs) in the galleries around the NEVOD water tank

Y-projection X-projection multiplicity m = 144 particles, zenith angle  = 57

BACKUP: Muon bundle event in the DECOR SMs

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