Abstract
Intensive development of foreign economic relations, a significant increase in the number of their participants, and the changes in customs policy in the context of the emergence of a market economy require the customs services to ensure high-performance, effective customs control of goods, vehicles, and belongings of people traveling across the state border. One of the defining integral elements in the daily inspection work of customs operatives is their use of technical means of control, without which it is now impossible to ensure the timeliness, quality, and culture of control at the border. The operational tasks of the customs services, requiring the use of technical means of customs control, are fundamental for understanding the role and place of the operational activities in the customs services. The issue is worth discussing, thus, the given paper will consider the use of electron bremsstrahlung for customs control of drugs at the border.
Introduction
High efficiency of control is achieved by the complex application of technical means in each specific area of customs control. For checking each kind of object moved across the state border, certain types of technical means must be used. Good knowledge of operational and technical capabilities, modern techniques and methods of their application, mastering practical skills of working with them can ensure a high professional level of customs control, starting with a reasonable calculation of duties and ending with the identification of contraband items.
Technical means of customs control is a complex of special means used by services directly in the process of operational control of all types of objects moved across the border. Objects are understood as hand baggage and accompanied luggage of passengers and transport employees, all types of cargo, international mail, international transport vehicles, and, in exceptional cases, specific people (when there are sufficient grounds to believe that they are carriers of contraband goods). Technical means of control are a necessary “weapon” for operational workers of the customs service, the use of which ensures the economic and state security of the country. The given paper will discuss the use of electron bremsstrahlung for control of drugs at the border.
Impact of Radiation
Scanning is safe for those who cross the border; the consequences may arise for people working with these devices. In medical practice, for hazardous working conditions, specialists who work with radiation receive various wage increases. For a person who undergoes an X-ray screening procedure once a month, it is not dangerous if he or she is outside the vehicle during scanning (Ivashova & Kiida, 2019). As a rule, two people always work at the inspection complexes, and one of them must take the driver and passengers outside the radiation exposure into a safe zone. The equipment is tested annually, and a special examination protocol is issued.
The main processes of interaction of X-ray radiation with a substance at the energy of quanta of the electromagnetic field (photons) less than 106 eV are photoelectric absorption and scattering. In this case, the physics of phenomena is completely adequate to the physics of the formation of X-ray radiation. Photoelectric absorption of X-ray radiation occurs when X-ray photons interact with atoms of a substance. Photons hitting atoms knock electrons from the inner shell of the atom. In this case, the primary photon completely spends its energy to overcome the binding energy of the electron in the atom and imparts kinetic energy to the electron. As a result of the energy rearrangement of the atom, which occurs after the emission of a photoelectron from the atom, characteristic X-ray radiation is formed, which, when interacting with other atoms, can cause a secondary photoelectric effect.
This process will continue until the photon energy becomes less than the binding energy of electrons in the atom. It is very important to note that the process of attenuation of radiation when passing through a substance depends not only on the energy of photons and the wavelength of radiation but also on the atomic number of the substance in which photoelectric absorption occurs (Jakubassa-Amundsen, 2018). The scattered radiation generated when passing through a substance is due to the fact that under the action of an electric field the electrons receive an alternating acceleration. As a result, they themselves emit electromagnetic waves with a frequency that coincides with the frequency of the primary radiation and the changed direction of radiation (the so-called coherent scattering) or due to the interaction of photons with free or weakly bound electrons of an atom of a substance (Kuniev & Bielova, 2019). Thus, as a result of photoelectric absorption of X-ray radiation in the substance and scattering, part of the energy of the primary radiation remains in the form of characteristic and scattered radiation, part of the energy is absorbed, and part is converted into the energy of charged particles – electrons.
Operation
Within 5-15 minutes, without opening and unloading the vehicle, customs officers receive an “image” of the vehicle and the goods transported in it. The inspection complex has doubled the speed of checking cars that pass the customs. Specialists work outside the sanitary zone; there is practically no radioactive radiation in the field. Employees are provided with personal dosimeters with which they can monitor the level of radiation. In practice, the process is the following: a truck or a passenger car drives into a spacious box with a scanning device. A customs officer checks the image of the “insides” of the car on the monitor.
X-rays transmitted through an object or substance are attenuated to varying degrees depending on the density distribution of their material. Thus, it carries information about the internal structure of the object, forms an X-ray image of the translucent object, which is then converted into an adequate optical image perceived by the operator’s eyes. The resulting scattered radiation does not carry information about the internal structure of the object and only worsens the quality of the formed image. The main requirements for X-ray image converters are maximum information content of the X-ray image at the lowest possible absorbed dose of radiation by the translucent object and optimal conversion of the X-ray image into an optical one, which ensures that the operator receives the maximum information contained in the shadow X-ray image.
The quality of an X-ray image is mainly determined, by contrast, brightness, non-sharpness, and resolution. The lower the level of scattered radiation, the higher the image contrast (Mahmoo, 2019). Real radiation sources produce a diverging beam of rays emerging from the focal spot of the anode of the X-ray tube, and the intensity of the X-ray radiation decreases in inverse proportion to the square of the distance from the focus of the X-ray tube. To obtain a higher radiation intensity in the plane of the observation screen and, therefore, higher brightness of the screen glow at a given X-ray tube power, it is advantageous to bring the focus of the tube and the screen as close as possible to the object under study. However, depending on the distance from the focus of the tube to the surface of the translucent object and from the surface of the object to the X-ray image converter (screen), distortion of geometric relationships occurs in the shadow X-ray image: structures of the same size, located at different distances to the focus of the X-ray tube are significantly different by the shape and area of the shadow. Since the size of the focal spot of the tube has a finite value, the transition from the highest image brightness to the area of full shadow occurs gradually – instead of a sharp border, a transitional penumbra region is formed. The contrast that provides a given probability of detecting an object is usually called the threshold contrast (Singh et al., 2015). This parameter is significant because practically the operator does not know where and when the “forbidden” object will appear in his field of vision.
Types Application
The brightness of the image, in addition to the power of the X-ray source, depends to a large extent on the properties of the used X-ray screens and detectors, which are characterized by rather high parameters of the energy output of luminescence, a high level of absorption and a high coefficient of spectral compliance with the human eye. Resolution is the ability to give clear, separate images of two small objects close to each other. The resolution limit is called the smallest linear (for X-ray inspection equipment) or angular distance between two objects, starting from which their images merge. In practice, it is customary to estimate the value of the resolution by the number of lines per 1 mm, and the thickness of the lines is equal to the thickness of the intervals between them.
Customs authorities began to be equipped with this type of X-ray inspection camera at the end of the ‘70s. At that time, samples of fluoroscopes were presented on the market, meeting the requirements of the organization and the technology of customs control. The Rapiscan 522 X-ray screening system is designed for use at airports to screen hand luggage and baggage carried by passengers on board an aircraft. Rapiscan 526 is the next generation of X-ray inspection systems. The ergonomic, durable, and reliable control panel allows an operator to easily control the inspection system, as well as select the desired parameters for image acquisition and processing. Implementation of the image processing unit in the form of a mono-board made it possible to significantly reduce the connections, which provides a higher reliability of the unit; post-processing technology ensures high image quality.
Conclusion
It is possible to state that the operational tasks of the customs services requiring the use of technical means of customs control are fundamental for understanding the role and place of the operational activities in the customs services. It can be concluded that despite the noticeable successes of customs authorities in organizing control using technical means, this direction of control is now in the process of being improved; vigilance and adherence to principles are required from the customs control authorities. Only in this case it will be possible to achieve tangible results, as well as to reduce and prevent illegal export and import of drugs and other objects of control at the customs.
References
Ivashova, L. M., & Kiida, L. I. (2019). Digitalization of customs procedures: The current situation and prospects of customs development.Public Administration and Customs Administration, 3, 218–230. Web.
Jakubassa-Amundsen, D. H. (2018). Electron-electron-photon polarization correlations in high-energy bremsstrahlung.Physical Review A, 98(6). Web.
Kuniev, Yu. D., & Bielova, D. S. (2019). The customs procedure customs warehouse: Theoretical aspects.Legal Position, 2, 60–69. Web.
Mahmoo, R. (2019). ‘Cross-border electronic commerce’: Challenges for customs administrations and the way forward.Customs Scientific Journal, 2, 16–35. Web.
Singh, T., Kahlon, K. S., & Dhaliwal, A. S. (2015). Role of polarization Bremsstrahlung in the formation of thick target Bremsstrahlung spectra in the energy range of 5-10 keV.X-Ray Spectrometry, 41(3), 172–175. Web.