SU1583806A1 - Scanning introscope - Google Patents

Abstract

The invention relates to non-destructive testing of materials and products, namely, radiation introscopy, and can be used to control materials and products, such as baggage, during customs inspection. The purpose of the invention is to increase the information content by identifying areas of a controlled object with a given chemical composition. In the device containing the emitter 1, unit 2 scan of the monitored object 15, one-dimensional array detector 3 radiation, multiplexer 4, analog-to-digital converter 5 with a normalizer on the input, block 6 of video memory, block 9 of control, video control unit 8 and block 14 of color coding , a memory block 7, a logarithm 10, a buffer memory block 11 and 12, and a comparator 13 are inserted. The determination of the material attenuation coefficients of the test object for two different radiation energies generated by emitter 1 is stored using logarithm 10 These values in the buffer memory blocks 11 and 12, the analysis of the ratio of the attenuation coefficients for each image point by means of the comparator 13, the change in the color of the shadow pattern areas depending on this ratio using the memory block 7 and the color-coding block 14 areas and elements of the controlled object with a given chemical composition. 3 il.

Description

The invention relates to non-destructive testing of materials and products, namely, radiation introscopy, and can be used to control materials and products, such as baggage, during customs inspection, where it is necessary to evaluate the chemical composition of internal heterogeneous areas of controlled objects during their movement.

The purpose of the invention is to increase the information content by identifying areas and elements of a controlled object with a different chemical compound.

FIG. 1 shows a functional diagram of a scanning introscope; in fig. 2 - a variant of the functional block of the control unit; in fig. 3 is an example of the dependence of the X-ray intensity on time.

The scanning introscope contains (Fig. 1) emitter 1, scanning engine 2 of the object being monitored, one-dimensional radiation detector 3, multiplexer 4, analog-digital converter (11AP) 5 s with a normalizer at the input, block 6 video memory 5 memory block 7, video monitoring the block (WKB) 8, the block 9 of the control s logarithmator 10, the blocks 11 and 12 of the buffer memory, the comparator 13 and the block 14 of color coding. The scanning mechanism 2 moves the object to be monitored 15.

The outputs of the one-dimensional matrix radiation detector 3 are connected to the corresponding information inputs of the multiplexer 4, the output of which is connected to the information input of the ATP 5 connected to the input of the logarithm 10 and to the information input of the video memory block 6. The video memory block b is connected to the information input of the color-coding block 14 connected by the functional conversion input to the output of the memory block 7 and the output to the input of the video spacing block 8. The output of the logarithm 10 is connected to the information inputs of the buffer memories 11 and 12, the outputs of which are connected respectively, to the first I and second information inputs of the comparator 13 connected to the information input of the memory unit 7. Control unit 9 is connected

the first output to the control inputs of the radiator 1 and the scanning mechanism 2, the second output to the address inputs of the multiplexer 4 and A1Sh 5, to the address inputs of the 11 and 12 blocks of the buffer memory, the third output to the sync inputs of the video memory block 6 and the memory block 7 and fourth and fifth

outputs - to the recording inputs of blocks 11 and 2 of the buffer memory, respectively.

The content control unit 9 (FIG. 2) is a programmable controller 16, a clock generator 17, a memory controller 18 and a pulse counter 19. The clock generator 17, whose input is the input of the introscopic start, is connected first, second and third

Q outputs respectively to the input of the programmable controller 16, the first output of which is the first output of the block, to one input of the memory controller 18 and to the information output

5 to the input of the pulse counter 19, the output of which is the second output of the block. The overflow output of the pulse counter 19 is connected to another input of the memory controller 18, the output

Q which is the third output of the block. The second output of the programmable controller 16, which is the fourth output of the block, is connected to the zeroing input of the pulse counter 19, and the third output of the programmable controller 16 is the fifth output of the block, on which the write pulse of the buffer memory block 12 is generated.

FIG. 3 denotes: I - intensity of radiation in time T ;, U, voltage on radiator 1; Tt and T- are the moments of the survey of 3 radiation detectors.

The scanning introscope operates as follows.

At the time T0 (Fig. 3), when the introscopy is launched, the control unit 9 generates a pulse including the emitter 1 and the scanning mechanism 2. In the moment -. T1, corresponding to voltage AND at radiator 1, multiplexer 4 interrogates a one-dimensional matrix detector of radiation 3, the signal from the output of which is normalized and digitized into A1Sh 5. The output signal of ADC 5 is recorded in video memory block 6 and through logarithmator 10 is entered into the block of buffer 11 memory. The logarithm 10 generates a signal proportionally

five

exponent of the exponent of the attenuation function in expression (1). At the moment Tr, corresponding to the voltage Uj on the emitter 1, the radiation detector 3 is again polled by multiplexer 4, and the information from their outputs goes to the buffer memory unit 12. The controlled object 15 during this time practically does not change its location, and therefore each of its elements turns out to be luminous, as it were, twice for two radiation energies corresponding to the voltage of the emitter supply voltage U1 and U7. I. The choice of U is determined by the chemical composition and thickness of the object under test 15, and for most cases U2 (1/2) U, can be accepted. The buffer memory unit 11 is a static memory with a volume equal to the number of 3 radiation detectors. The buffer memory unit 12 can be executed similarly to the buffer memory unit 11 or in the form of a register for latching a signal from only one radiation detector 3. In this case, at the second survey of the corresponding radiation detector 3 at the time T, the signal of the 1st radiation detector 3 is recorded in the buffer memory block 12 and at the same time the output of the 1 radiation detector 3 received at the output of the buffer memory block 11 at time T, (fig.Z). These signals are compared in comparator 13.

The attenuation of the x-ray intensity is described by a known exponential law.

Where

I «1„

I0exp (-),

(one)

f

-intensity falling on a controlled object 1 5

and sunshine

-the intensity of the radiation transmitted through the controlled object 15;

- attenuation coefficient of radiation by the material of the controlled object 15;

-the density of the material of the controlled object 15;

-the thickness of the material of the controlled object 15.

Depending on the radiation energy and chemical composition of the material of the controlled object 15, one or another process of interaction of the radiation with the material of the controlled object 15 may prevail. For example, the characteristic mode of operation of radiation 1 when inspecting baggage is 80-140 kV. This corresponds to an effective energy of radiation quanta E 50-100 keV. In this energy range, for example, for iron and heavier elements (with Z: 13, the photoeffect (m C) predominates during the interaction), and for 40

45

50

More than light elements (with Z 13), the osCoFunctional attenuation factor i / 55 is caused by the radiation shaking, due to the dependence of the melting on nnp - mainly by scattering (and C) and

the dependence of the attenuation on the voltage U on the radiator 1 and the chemical composition of the material of the controlled object 15 in the form

weakly depends on both the radiation energy and the chemical composition of the material of the object under control 15

6

+ 6

K.

+ K2Z A

(2)

de C,

(Y are the attenuation coefficients of radiation by the material of the object under test 15, due, respectively, to the photoelectric effect and scattering; and K2 are constants;

Z is the atomic number of the material of the object under control 15; A is the atomic weight of the material

controlled object 15. In introskop implemented algorithm

kind of

1t lexpC-Kfx)

K f

M2

(3 -t4 - exprx) - px

where I, I - the intensity of the past

 I 2

radiation at times T and Tr, respectively; p, and (U2 are the attenuation coefficients for energies at U1 and tL; H is the threshold level,

defined by the physical properties of the areas to be distinguished and the background.

The effect of the magnitude o is within the limits delimited by the dimensions of the controlled object 5, on the one hand, and the minimum thickness of metallic inclusions in the material of the controlled object to be detected, on the other hand, is insignificant.

Depending on the radiation energy and chemical composition of the material of the controlled object 15, one or another process of interaction of the radiation with the material of the controlled object 15 may prevail. For example, the characteristic mode of operation of radiation 1 when inspecting baggage is 80-140 kV. This corresponds to an effective energy of radiation quanta E 50-100 keV. In this energy range, for example, for iron and heavier elements (with Z: 13), a photo effect (m C) predominates during the interaction, and for bo

The lighter elements (with Z 13) attenuation of the radiation is mainly due to scattering (and C) and

weakly depends on both the radiation energy and the chemical composition of the material of the object under control 15.

Thus, in order to assess the chemical composition of the material of the object under control 1 5 in the specified radiation energy range, it is necessary to estimate the change in the attenuation value when the radiation energy changes. So, for E, 50 keV and 100 keV, the attenuation coefficient for iron, respectively (Z 26 ) and water (from Z e 7,8) are

. "" -

 , 93-0.37) cMV Nm (0,22-0,17) smgg-.

and

In the first case, the attenuation has changed significantly (5 times), and in the second case is not significant.

The comparator 1 3 must be set up in such a way as to isolate the specified changes in the attenuation of the radiation and control the color coding when generating the shadow image at WKB 8. Comparator 13 is a conventional digital comparator, supplemented by a multiplier at a single input. Usually H 2k, where K is a positive integer (K 0,1,2 ...), and therefore multiplication is achieved by simply switching the bits on one of the inputs. In the general case, a digital multiplier is placed, on one input of which the threshold H is set. Depending on the ratio p, H (t or nx, Hpt at the output

the comparator 13 produces a signal that is recorded in the memory block 7, which is a one-bit memory of the same size as the electronic memory of the video memory block 6. Thus, the ratio is checked for each image element (L,% N | c and, depending on it, a conclusion is made about the chemical composition of the material of the object under test 15. The memory block 7 controls the selection of the conversion function in the color-coding block 14. Thus, elements of the controlled object 15, having a certain chemical composition, can be distinguished at VKB 8.

The use of the invention will make it possible to increase the information content of the image of the object under control by highlighting its areas and elements whose material has a certain chemical composition, for example, to reveal unauthorized investments by customs control.

in baggage-at

Q

five

five

0 30 35

40, 50

„

Claims (1)

Scanning microscopes containing a radiator, a scanned object's scanning mechanism, a control unit with a start input and with three outputs, a one-dimensional array radiation detector, a multiplexer, an analog-to-digital converter with an input normalizer, a video memory block, a color-coding block with information the input and input of the functional conversion and the video monitoring unit, the input of which is connected to the output of the color-coding unit, the control unit is connected to the first output control unit by the second output to the address inputs of the multiplexer and the analog-digital converter and the third output to the sync input of the video memory unit connected by the output to the information input of the color-coding unit and the information input to the output of the analog-digital converter, information the input of which is connected to the output of a multiplexer connected by information inputs to the corresponding outputs of a one-dimensional matrix radiation detector, characterized in that increase informativity due to detection of areas and elements of the monitored object with a given chemical composition, a logarithmizer, two buffer memory blocks, a comparator and a memory block are entered into it, and the control unit is equipped with fourth and fifth outputs connected to the recording inputs, respectively the first and second blocks of the buffer memory connected by address inputs to the second output of the control unit, information inputs to the output of the logarithm and outputs to the first and second information inputs of the computer, respectively Ator, the output of which is connected to the data input of the memory unit being connected to the third input of synchronism output control unit and output - to an input of a functional block transform coding of color and logarifmatora input connected to the output of analog-to-digital converter. Start Go Editor V. Bugrenkova Compose V. Kostyukhin Tehred L. Serdyukova Proofreader M. Pojo Order 2249 Circulation 499 VNIITI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 4/5, Moscow, Zh-35, Raushsk nab. 113035 . 2 Subscription