Muonography of large natural and industrial

objects

ISCRA 2019, 25 June 2019, MEPhI, Moscow, Russia

T.V. Shchedrina, A.K. Abiev, A.V. Bagulya, M.M. Chernyavsky,

A.B. Dashkina, A.A. Dimitrienko, A.A. Gadjiev, M.S. Gadjiev,

V.I. Galkin, A.A. Gippius, L.A. Goncharova, V.M. Grachev,

N.S. Konovalova , A.K. Managadze, N.M. Okateva

N.G. Polukhina , T.M. Roganova, N.I. Starkov ,

A.A. Teymurov, V. Tioukov, S.G. Vasina and P.I. Zarubin.

ISCRA 2019, 25 June 2019, MEPhI, Moscow, Russia

Lebedev Physical Institute, Russian Academy of Sciences, Moscow, Russia Institute of History, Archeology and Ethnography, Dagestan Scientific Centre, Russian Academy of Sciences, Makhachkala, Republic of Dagestan, Russia Dagestan State University, Makhachkala, Republic of Dagestan, Russia National University of Science and Technology MISiS, Moscow, Russia Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia National Research Nuclear University MEPhI, Moscow, Russia Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia INFN Sezione di Napoli, Naples, Italy Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia

Outlook The principle of muonography and application areas

Nuclear emulsions as a tracking detector

advantages of emulsion tracking detector

PAVICOM scanning station

Exposure in citadel of Naryn-Kala, Derbent

Simulation and data analysis

Conclusions and perspectives

ISCRA 2019, 25 June 2019, MEPhI, Moscow, Russia 3

The principle of X-ray radiography

ISCRA 2019, 25 June 2019, MEPhI, Moscow, Russia 4

DETECTOR

Point-like source Detector size more or equal to the target size X-rays can pass a few cm of high density matter Density variation of the target is transformed into coordinate intensity variation on the detector

DETECTOR

The principle of muonography

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Distributed radiation source Detector is point-like in respect to the target Muons can pass about a km of investigated objects Density variation of the target is transformed into angular intensity variation on the detector

DETECTOR

Angle to coordinate transformation is required to see this picture

DETECTOR

Atmospheric muons

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Protons coming from space

muon flux is the penetrating component of cosmic rays; intensity at the see level: 10,000 µ / m2 / min; muons are capable of crossing hundreds of meters of rock with absorption

corresponding to the thickness of the substance they pass through; the maximum depth where the highest energy muons were recorded is about 8,600 m

in terms of water equivalent, which roughly corresponds to 2 km of rocky soil.

Application areas of MUONOGRAPHY

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Application areas of MUONOGRAPHY Active volcano STROMBOLI, Italy

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Rock thickness and mountain profiles as seen by the detector

Difference between the observed muon flux and the one expected from Monte Carlo simulation Color scale represents muons counts.

the crater region seen from the detector location

Detector location and crater in a map from the Digital Elevation Model The color scale indicates the elevation in meters.

Rock density changes, dense lava channels and low density magma supply channels at Stromboli

suggest a strong control of the crater area structure!

Application areas of MUONOGRAPHY Great East Japan Earthquake

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Application areas of MUONOGRAPHY Ice-bedrock interface of alpine glaciers

Detector frames installed at the rock wall in the railway tunnel

Muonography first time applied to the field of glaciology. The technique provides important information when other geological procedures such as radar and seismic inspections can not be used

Jungfrau Railway

The project is financially supported by the Swiss national Science Foundation

Advantages of emulsion tracking detector

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High sensitivity and excellent tracking

capability with angular resolution few mrad

and spatial resolution less than 1µm

High information capacity

Simple design and relatively small < 1m2

Easy transportable to the object

Able to work in harsh environments

Do not require power supply

NUCLEAR EMULSION as a tracking detector

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June25_Presentation_14_ShchedrinaT_Anim.gif

PAVICOM scanning station

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CMOS camera

1280×1024 pixel

256 gray levels

376 frames/sec

(Mikrotron MC1310)

XY stage (Micos)

0.1 μm nominal

precision

Emulsion Plate

Z stage (Micos)

0.05 μm nominal

precision

Illumination system, objective (Oil 50× NA 0.85)

and optical tube (Nikon)

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Principle of the automatic emulsion scanning

Movable stage

Image Processing board Motor control card

20 Tomographic Images taken through 40-micron Emulsion Layer

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Naryn-Kala citadel in Derbent

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Detector exposure

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Scheme of detector exposure

Detector construction

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Inox steel frame

Elastic (rubber) layers

Enveloped emulsion films

2 months of exposure

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Simulation with Geant 4 Wall thickness = 0.5 m

Wall thickness = 1.5 m

Sandstone density 1 = 2.00 g/cm3

Sandstone density 2 = 2.65 g/cm3

Soil material density 1 = 1.78 g/cm3

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Experimental data costgdz

dxtx

sintgdz

dyty

Conclusions The first results of test experiment with using the muonography method are reported

The technique makes it possible to obtain reliable experimental data interpretation for the structure of investigated objects

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Detectors installation on the western slope of the fortress outside the walls of the building to obtain 3D tomogram of the underground cross-shaped dome structure under discussion, simulation in progress

Optimization automated scanning system PAVICOM for increasing scanning speed in progress

and perspectives

Backup slides

Data processing for muonography

Microtracks

30 GB / film (120 cm2)

Filtered microtracks

1.5 GB / film (120 cm2)

Volume tracks

500 MB / 5 emulsion films

Full detector (1 m2)

40 GB

Detectors made with nuclear emulsions

Track reconstruction algorithm

Image processing • substitution of the light field

background • image filtration • applying threshold and binarization

Grains reconstruction • finding clusters on each depth • reconstructing grains in each

field of view

Microtracks reconstruction for each emulsion layer

• finding all "links" - pairs of clusters • selecting links that have grain

density along it over the threshold (prepare microtrack candidates)

• histogramming of these links and finding microtracks

• fitting of the found microtracks

~15M links -> ~150k selected links -> ~1500 microtracks

First test experiments in Russia • The object of the first test experiment

with emulsion track detectors was a steel column 23 tons in weight, MSU

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• The second muon radiography test was with a couple of chassis dynamometer discs and an inertial element of the test bench 40 tons in total weight

The third experiment, Obninsk RAS

The experiment goal was to assess the possibility of

“finding” a cavity (elevator mine shaft at a depth of 30

m) in the bulk of ground and to register the difference in

fluxes of atmospheric muons at the earth surface and at

a depth after passing the layer of ground

Data analysis

Scheme of the experiment in a mine shaft at a depth of 30 meters (top view). The orientation of axes X and Y at the analyses of films is shown.

Exposure time were two and four months 4 modules with 10 OPERA-like emulsion Area of the emulsion in total is about 0.24 m2

for each detector Each tracking detector has 2 triplets and 2

doublets

Up to today one detector of two was scanned, processed and analyzed with 4 months exposure. The second one is in the queue.

The track density as a function of the 2 components TX and TY of the track slope. .

To select original tracks from other background tracks, the original two-dimensional distribution (TX, TY) subtracted averaged over the azimuthal angle Φ background.

Data analysis