NATO Advanced Research...

Selectively sensitive sensor to determine the explosives

Surik Khudaverdyan

Ashok Vaseashta

Stepan Tsaturyan

Narine Merhabyan

Taron Hovhannisyan

June 1-3, 2015, Aghveran

NATO Advanced Research Workshop

1. The problem statement

2. The solutions and approaches

3. Applications

4. Technical advantages

Content


June 1-3, 2015. Aghveran



There are three main factors, which are feasible to identify the explosivesin distance (~5m), using the phenomenon of molecular substancefluorescence of the Nitrogen oxide (NO) caused by photolysis of the steamconcentrated on the surface of the explosive.

1. The Nitrogen oxide (NO) nitro group is the widely used chemical component in most explosives.

2. (C–NO2, N–NO2, O–NO2) functional groups have the minimum connection energy and during the photolysis process the Nitrogen oxide (NO) portion is separating and producing the fluorescence (236 nm).This is giving the ability to use the spectral analysis of the fluorescence wave and identify the explosive chemicals.

3. The molecules of explosives exhibit a wide absorption spectrum which is specific for Nitrogen oxide (NO) molecules. Therefore, in many cases, we can use for absorption the same radiation source which is used for emission spectra.



When irradiated by a Krypton (Kr) laser beam (310 nm wavelength), the vapors of explosive materials undergo photolysis and, as a result, electronically excited molecules of Nitrogen oxide (NO), Nitrogen (N2) and Oxygen (O2) are formed. This excitation is accompanied by fluorescence at corresponding wavelengths.

Registering and analyzing that corresponding wavelengths we are getting the information about the particular explosive(s).

Table 1 is represents the information about the explosives and the number of molecules in a volume unit.

The dependence of the intensity of the fluorescence wavelength from the Spector

106

105

104

103

102

101

100

10-1Inte

nsi

ty (

nu

m. m

ol. i

n a

vo

lum

e u

nit

)

232 233 234 235 236 237 238 239 240

Wavelength (nm)

N2

NO

O2



Type of the explosive Vapor densityВВ (order of magnitude)

Number of molecules explosives per trillion of molecules of air

Number of molecules explosives per cm3 of air

Grams of explosives per cm3 of air

Nitroglycerine(NG) 106 1013 10-9

Trotyl (TNT) 104 1011 10-11

PETN 100 - 101 108 - 109 10-14 - 10-13

Cyclonite (RDX) 100 108 10-14

C-4 10-1 107 10-15

Ethylene glycol denitrate (EGDN) 108 1015 10-7

The number of molecules in a volume unit



Light filter Absorption filter Interference filter

Possible Solutions



Thus, we are separating the following applicable problems.

• The need for development of new most efficient sensors withselective sensitivity

• The need for development of the new methodology for dataacquisition, processing algorithms and most effective technics forthe analyzing the Spector.

We think that the presented methodology that we are developing for thesmart photosensor could be useful and acceptable for analyzing theoptically transparent natural objects as well, like water. To analyze theminerals and the chemicals containing in the water.

The need of smart photodiodes



F

X

λ4

λ3

λ1λ2

Xm(V)

F04

F03

F02

F01

X moves through the surface

0 – surface

X - deepenes

Intensity

hν

The process of absorption of different channels in the structure is used



F

x

1 2 <

F0

F01

F02

1 2 <

15

F

xxm

Light Intensity

Deepness

xm

Light Intensity

Deepness

The process of absorption of different channels in the structure is used



М

d0

Area of the driftage

xm

2 xm

Diffusion of electrons

1

2

EF

x

h

Idr1 Idr2

Idiff.

Iemis.

Itot

d1

I II III

m

In as results the photo current is generation in 2-nd and 3-rd regions. In the first region

current is not generated.

Xm-the minimumpotential of theelectrons andthe touch point ofthe threshold

Electrons

diffusionDrift zone

The short introduction of the photodetector



Deflation zone

12

dxeeSqFI m

0drp-n transition (Xm – d) depletion layer dreff current

P-zone, diffusion current

Photocurrent produced by integral radiation

w

eeFqSI

i

dx

i j

i

ji

ji

i

mji

1)(0

,

,

dn ew

LSqFI

10diff

The mathematical modeling formulas of the electronic processes

calculations



0 0.5 1 1.5 2

1.8

1.4

1

0.6

0.2

I, x10-11, A

Xm, x10-6, cm

Photocurrent dependency by Xm for the

sequentially identified waves

grafik

0

1E+13

2E+13

3E+13

4E+13

5E+13

6E+13

300 350 400 450 500 550 600

grafik

6

4

5

3

2

1

IntensityF0

x1013 քվ/սմ2·վրկ

Spectral view of the radiation

300 350 400 450 500 550 600 λ, nm

The spectral distribution of the radiation intensity



n n

p+ +

F0

0

xp,n

X0

d

x

SiO2

SiO2

Resistive contact

Resistive contact

n+

Si

F0

p

SiO2

p

xx

oL

eeqFj

nn

1

12

1

2ln1

I

I

xi

pi

xx

ioi

L

eeq

jF

nini

1

12

The structure of the photodetector

Alternative photodetector used

Silicon based photodetector

ФД-20-30К



+ -

Ֆոտոընդունիչ

Համակարգիչ (Controller)

NI sbRIO 9636

Լազեր,

= 530 նմ

Prototype

Controller NI sbRIO 9636

Photodetector Laser, = 530 նմ

Համակարգիչ (Controller)

NI sbRIO 9636

Լազեր,

= 530 նմ


June 1-3. 2015 Aghveran

Laser,

= 530 նմIntensity by relative units

The room lighting and the laser beam spectors


June 1-3, 2015, Aghveran

28

1. High accuracy spectral measurements and analysis in the field

2. Simple production technology and small footprint

3. Multipurpose use

4. Self calibration

5. Low cost

6. The silicon based technology is used

The technical advantages


June 1-3 2015. Aghveran

Ecological and environmental – environmental conditions, food safety

Medical – Solar radiation, Physiotherapy, drugs analysis, blood analysis

Agricultural – Greenhouse and warm house technologies

Biotechnologies – D2 и D3 synthesis of vitamins, DNA analysis

Applications



Method and device for wavelength-sensitive photo-sensing

WO 2005078801 A1

http://www.google.ca/patents/WO2005078801A1?cl=en

Method and device for wavelength-sensitive photo-sensing using multiple

pn-junction

WO 2005098956 A1

http://www.google.ca/patents/WO2005098956A1?cl=en

Dual junction photoelectric semiconductor device

US 4318115 A

http://www.google.ca/patents/US4318115

Color separation in an active pixel cell imaging array using a

triple-well structure

US 5965875 A

http://www.google.ca/patents/US5965875

Apparatus for sensing the wavelength and intensity of light

United States Patent 4309604

http://www.google.com/patents/US4309604

The latest researches in this field



13. Kalkhoran N. M., Namavar F. (1997). Multi-Band Spectroscopic Photodetector Array.

U. S. Patent: US005671914A. Available

at: http://www.google.com/patents/US5671914

14. Khudaverdyan S., Dokholyan J., Khudaverdyan A., Grigoryan K.

(2007). Spectrophotometric filterless photodetector. J. Phys. D Appl.

Phys. 40 766910.1088/0022-3727/40/24/012 [Cross Ref]

Front Neuroeng. 2014; 7: 5.

Published online Feb 18, 2014. doi: 10.3389/fneng.2014.00005

PMCID: PMC3927122

Improved selectivity from a wavelength addressable device for wireless stimulation

of neural tissue

Улучшенная селективность от длины волны адресуемой устройством для

беспроводной стимуляции нервной ткани

Elif Ç. Seymour,1,† David S. Freedman,2,† Mutlu Gökkavas,3 Ekmel Özbay,3 Mesut

Sahin,4 and M. Selim Ünlü1,2,*

Author information ► Article notes ► Copyright and License information ►



Thank you.

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