Determination of Optimal Parameters of the X-Ray Source on the Basis of Compact Electron Accelerators

The paper discusses the issue of creating a monochromatic X-ray source based on a small-size electron accelerator to be used for the purposes of medical diagnostics. We carried out the simulation of X-ray spectra generated by an electron beam with the energy of 4-10 MeV in the targets of different materials and thicknesses and determined the optimal parameters of the target. The radiation intensity was estimated and sources based on different accelerators were compared, with due consideration of the simulation results.

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Some of these could also be operated in the energy range above lOMeV for experiments designed to determine at which energy level radioactivity can be induced in the irradiated medium. A linac with a maximum energy of 25 MeV was commissioned for the U.S. Army Natick Research and Development Labora tories in 1963. Its beam power was 6.5 kW at an electron energy of 10 MeV, 18 kW at 24 MeV. Assuming 100% efficiency, a 1-kW beam can irradiate 360 kg of product with a dose of 10 kGy/h. The efficiency of electron accelerators is higher than that of gamma sources because the electron beam can be directed at the product, whereas the gamma sources emit radiation in all directions. An efficiency of 50% is a realistic assumption for accelerator facilities. With that and 6.5 kW beam power an accelerator of the type built for the Natick laboratories can process about 1.2t/h at 10 kGy. In Odessa in the former Soviet Union, now in the Ukraine, two 20-kW accelerators with an energy of 1.4 MeV installed next to a grain elevator went into operation in 1983. Each accelerator has the capacity to irradiate 200 t of wheat per hour with a dose of 200 Gy for insect disinfestation. This corresponds to a beam utilization of 56% (9). In France, a facility for electron irradiation of frozen deboned chicken meat commenced operation at Berric near Vannes (Brittany) in late 1986. The purpose of irradiation is to improve the hygienic quality of the meat by destroying salmonella and other disease-causing (pathogenic) microorganisms. The electron beam accelerator is a 7 MeV/10 kW Cassitron built by CGR-MeV (10). An irradiation facility of this type is shown in Figure . Because of their relatively low depth of penetration electron beams cannot be used for the irradiation of animal carcasses, large packages, or other thick materials. However, this difficulty can be overcome by converting the electrons to x-rays. As indicated in Figure 9, this can be done by fitting a water-cooled metal plate to the scanner. Whereas in conventional x-ray tubes the conversion of electron energy to x-ray energy occurs only with an efficiency of about %, much higher efficiencies can be achieved in electron accelerators. The conversion efficiency depends on the material of the converter plate (target) and on the electron energy. Copper converts 5-MeV electrons with about 7% efficiency, 10-MeV electrons with 12% efficiency. A tungsten target can convert 5-MeV electrons with about 20%, 10-MeV electrons with 30% efficiency. (Exact values depend on target thickness.) In contrast to the distinct gamma radiation energy emitted from radionuclides and to the monoenergetic electrons produced by accelerators, the energy spectrum of x-rays is continuous from the value equivalent to the energy of the bombarding electrons to zero. The intensity of this spectrum peaks at about one-tenth of the maximum energy value. The exact location of the intensity peak depends on the thickness of the converter plate and on some other factors. As indicated in Figure

Safety of Irradiated Foods ◽

10.1201/9781482273168-31 ◽

1995 ◽

pp. 40-40

Keyword(s):

Electron Beam ◽

Electron Energy ◽

Maximum Energy ◽

Metal Plate ◽

Beam Power ◽

X Rays ◽

X Ray ◽

Emit Radiation ◽

Electron Accelerators ◽

Gamma Sources

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Electron beam control using experimentally measured transport matrices

Laser and Particle Beams ◽

10.1017/s0263034600007205 ◽

1994 ◽

Vol 12 (1) ◽

pp. 17-21 ◽

Cited By ~ 1

Author(s):

C.B. McKee ◽

John M.J. Madey

Keyword(s):

Spatial Distribution ◽

Electron Beam ◽

Electron Accelerator ◽

Electron Beams ◽

Transport Systems ◽

Evoked Responses ◽

Free Electron Lasers ◽

High Brightness ◽

Electron Accelerators

Free electron lasers (FELs) place very stringent requirements on the quality of electron beams. Present techniques for commissioning and operating electron accelerators may not be optimized to produce the high brightness beams needed. Therefore, it is proposed to minimize the beamline errors in electron accelerator transport systems by minimizing the deviations between the experimentally measured and design transport matrices of each beamline section. The transport matrix for each section is measured using evoked responses. In addition, the transverse phase space of the beam is reconstructed by measuring the spatial distribution of the electrons at a number of different betatron phases and applying tomographic techniques developed for medical imaging.

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Analysis of Nanopowders by Small-Angle X-Ray Scattering Method’s

Siberian Journal of Physics ◽

10.54362/1818-7919-2012-7-4-107-116 ◽

2012 ◽

Vol 7 (4) ◽

pp. 107-116

Author(s):

Sergey Bardakhanov ◽

Ludmila Vikulina ◽

Vladimir Lysenko ◽

Andrey Nomoev ◽

Sergey Poluyanov ◽

...

Keyword(s):

Distribution Function ◽

Size Distribution ◽

Small Angle ◽

Electron Accelerator ◽

Size Distribution Function ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

The possibility of application of small-angle X-ray scattering (SAXS) for nanopowders analysis was studied. The research for eight silica powders (including four powders obtained by the authors with help of electron accelerator) was conducted. The possibility of application of small angle X-ray scattering for determination of size distribution function of nanoparticles was shown

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Photon flux determination of a liquid-metal jet X-ray source by means of photon scattering

Journal of Analytical Atomic Spectrometry ◽

10.1039/c9ja00127a ◽

2019 ◽

Vol 34 (7) ◽

pp. 1497-1502 ◽

Cited By ~ 3

Author(s):

Malte Wansleben ◽

Claudia Zech ◽

Cornelia Streeck ◽

Jan Weser ◽

Christoph Genzel ◽

...

Keyword(s):

Electron Beam ◽

Liquid Metal ◽

Power Density ◽

Photon Flux ◽

Beam Power ◽

Photon Scattering ◽

X Ray ◽

Metal Anode ◽

Metal Jet

Liquid-metal jet X-ray sources promise to deliver high photon fluxes, which are unprecedented for laboratory based X-ray sources, because the regenerating liquid-metal anode is less sensitive to damage caused by an increased electron beam power density.

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Determination of carbon in sediments by electron beam X-ray excitation

X-Ray Spectrometry ◽

10.1002/xrs.1300020406 ◽

1973 ◽

Vol 2 (4) ◽

pp. 165-168 ◽

Cited By ~ 3

Author(s):

A. B. Poole

Keyword(s):

Electron Beam ◽

X Ray

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Determination of Chemical Valence State by X-ray Emission Analysis Using Electron Beam Instruments: Pitfalls and Promises

Analytical Chemistry ◽

10.1021/ac981214q ◽

1999 ◽

Vol 71 (14) ◽

pp. 2714-2724 ◽

Cited By ~ 12

Author(s):

John T. Armstrong

Keyword(s):

Electron Beam ◽

Valence State ◽

Emission Analysis ◽

X Ray

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Investigation of tube parameters on Xray spectra by MCNP5 code

Science and Technology Development Journal ◽

10.32508/stdj.v16i4.1592 ◽

2013 ◽

Vol 16 (4) ◽

pp. 20-25

Author(s):

Khanh Ai Tran ◽

Dung Thi Thuy Vo ◽

Loan Thi Hong Mai ◽

Nhon Van Mai ◽

Phuong Nguyen Dang

Keyword(s):

Quality Improvement ◽

Absorbed Dose ◽

Emission Spectra ◽

Bremsstrahlung Spectrum ◽

Dose Estimation ◽

X Ray ◽

Image Quality Improvement ◽

Mcnp5 Code ◽

Simulation Results

In diagnostic radiology, the determination of bremsstrahlung spectrum is essential for patient absorbed dose estimation and image quality improvement. In this paper, we surveyed the X-ray emission spectra of different peak voltages 50, 70, 85, 125 and 150 kV by using MCNP5 code. Besides, the effects of filter, collimator and anode material on X-ray spectra have also been investigated. The simulation results fairly agree with experimental spectra obtained by P.T. Talla et al. (2009)

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Deep Learning and Artificial Intelligence for the Determination of the Cervical Vertebra Maturation Degree from Lateral Radiography

Entropy ◽

10.3390/e21121222 ◽

2019 ◽

Vol 21 (12) ◽

pp. 1222 ◽

Cited By ~ 2

Author(s):

Masrour Makaremi ◽

Camille Lacaule ◽

Ali Mohammad-Djafari

Keyword(s):

Artificial Intelligence ◽

Deep Learning ◽

Cervical Vertebra ◽

Medical Diagnostics ◽

Great Success ◽

X Ray ◽

Treatment Timing ◽

Proposed Model ◽

The Right

Deep Learning (DL) and Artificial Intelligence (AI) tools have shown great success in different areas of medical diagnostics. In this paper, we show another success in orthodontics. In orthodontics, the right treatment timing of many actions and operations is crucial because many environmental and genetic conditions may modify jaw growth. The stage of growth is related to the Cervical Vertebra Maturation (CVM) degree. Thus, determining the CVM to determine the suitable timing of the treatment is important. In orthodontics, lateral X-ray radiography is used to determine it. Many classical methods need knowledge and time to look and identify some features. Nowadays, ML and AI tools are used for many medical and biological diagnostic imaging. This paper reports on the development of a Deep Learning (DL) Convolutional Neural Network (CNN) method to determine (directly from images) the degree of maturation of CVM classified in six degrees. The results show the performances of the proposed method in different contexts with different number of images for training, evaluation and testing and different pre-processing of these images. The proposed model and method are validated by cross validation. The implemented software is almost ready for use by orthodontists.

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