With the advancement of science, technology, and medical care, people are increasingly exposed to X-rays during hospital visits. Most know that chest X-rays, CT scans (though CT uses specialized X-ray technology), and X-ray machines emit radiation to penetrate the human body for diagnostic purposes. Yet few truly understand the X-rays themselves—how they’re generated and what makes them suitable for medical imaging. Let’s break it down clearly.
I. How Are X-Rays in X-Ray Machines Produced?
Medical X-rays require three core conditions for production, working together to generate the radiation used in diagnostics:
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X-ray Tube: A vacuum glass tube containing two electrodes—an anode (positive electrode) and a cathode (negative electrode). This tube provides the closed, vacuum environment necessary for electron movement.
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Tungsten Target: A tungsten plate (a metal with a high atomic number) serves as the anode of the X-ray tube. Tungsten is ideal because its high density and melting point can withstand intense electron bombardment.
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High-Speed Electrons: A high voltage is applied across the X-ray tube, accelerating electrons from the cathode to the anode at extremely high speeds. Specialized high-voltage transformers boost standard electrical voltage to the levels required for this acceleration. When these high-speed electrons collide with the tungsten plate, they ionize tungsten atoms (knocking electrons out of atomic orbits), and X-rays are generated in the process.
II. Key Properties of X-Rays: Why They Work for Medical Imaging
X-rays’ ability to penetrate the human body and enable disease detection stems from three fundamental properties, each critical to their medical application:
1. Penetrability
Penetrability refers to X-rays’ ability to pass through materials without being fully absorbed—something ordinary visible light cannot do. Visible light has long wavelengths and low photon energy; when it hits an object, most is reflected or absorbed, with little transmission. X-rays, by contrast, have short wavelengths and high energy. When irradiated on a material, only a portion is absorbed, while most passes through atomic gaps, exhibiting strong penetrability.
Two factors influence this property: – X-ray energy: Shorter wavelengths mean higher photon energy and stronger penetrability. – Material density: Denser materials (e.g., bones) absorb more X-rays and transmit less; less dense materials (e.g., muscles, fat) absorb less and transmit more. This differential absorption allows X-rays to distinguish between tissues of varying densities—forming the physical basis for X-ray fluoroscopy and radiography.
2. Ionization
When X-rays irradiate a substance, they dislodge extranuclear electrons from atomic orbits—a phenomenon called ionization. During processes like the photoelectric effect and scattering, photoelectrons and recoil electrons separating from their atoms are known as primary ionization. These electrons then collide with other atoms as they travel, dislodging more electrons—a process called secondary ionization.
In solids and liquids, ionized positive and negative ions recombine quickly and are hard to collect. But ionized charges in gases are easily collected, and the amount of charge can be used to measure X-ray exposure—forming the basis for X-ray measuring instruments. Ionization also enables gases to conduct electricity, triggers chemical reactions in certain substances, and induces biological effects in organisms. Importantly, ionization is both the basis of X-ray’s therapeutic effects and its potential for tissue damage.
3. Fluorescence
X-rays have short wavelengths and are invisible to the naked eye. However, when irradiated on specific compounds (e.g., phosphorus, platinum cyanide, zinc cadmium sulfide, calcium tungstate), the atoms become excited due to ionization. As these atoms return to their ground state, valence electrons undergo energy-level transitions, emitting visible or ultraviolet light—known as fluorescence. The intensity of this fluorescence is proportional to the amount of X-rays irradiated.
This property is the foundation of X-ray fluoroscopy. In diagnostic settings, it’s used to manufacture fluorescent screens, intensifying screens, and input screens in image intensifiers: – Fluorescent screens: Display real-time images of X-rays passing through human tissues during fluoroscopy. – Intensifying screens: Enhance film sensitivity during radiography, reducing required X-ray dose.
Choose NEWHEEK for Reliable X-Ray Machines
Weifang NEWHEEK Electronic Technology Co., Ltd. is a professional manufacturer specializing in the R&D, production, and sales of X-ray machines. Our products are engineered to meet international quality standards, catering to the needs of hospitals, clinics, and diagnostic centers worldwide.
If you have questions about X-ray machines, their operation, or customization options, feel free to contact us anytime:
Weifang NEWHEEK Electronic Technology Co., Ltd.
Tel: +86 19953639012
Post time: Dec-02-2025