Medical
Wea`am Mohammad Al-jarie
Dr. mokhleed zaza physics Medical applications of x-ray
Introduction:
X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz)
X-rays up to about 10 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 10 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities.[3]
Hard X-rays can penetrate some solids and liquids, and all uncompressed gases, and their most common use is to image of the inside of objects in diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays hardly penetrate matter at all; the attenuation length of 600 eV (~2 nm) X-rays in water is less than 1 micrometer.[4]
The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays).[5] Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays.[6] However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.[5][7][8][9]
Medical applications:
During the first four decades of this century many advances in medical radiation uses came from gradual improvements in equipment and techniques. The
Dr. mokhleed zaza physics Medical applications of x-ray
Introduction:
X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz)
X-rays up to about 10 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 10 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities.[3]
Hard X-rays can penetrate some solids and liquids, and all uncompressed gases, and their most common use is to image of the inside of objects in diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays hardly penetrate matter at all; the attenuation length of 600 eV (~2 nm) X-rays in water is less than 1 micrometer.[4]
The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays).[5] Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays.[6] However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.[5][7][8][9]
Medical applications:
During the first four decades of this century many advances in medical radiation uses came from gradual improvements in equipment and techniques. The
References: 1. ^ Novelline, Robert. Squire 's Fundamentals of Radiology. Harvard University Press. 5th edition. 1997. ISBN 0674833392. 2. ^ "X-ray". Oxford English Dictionary. Oxford University Press. 3rd ed. 2001. 3. ^ Holman, Gordon; Benedict, Sarah (1996-09-23). "Hard X-Rays". Solar Flare Theory Educational Web Pages.Goddard Space Flight Center. Retrieved 2011-03-09. 4. ^ "Physics.nist.gov". Physics.nist.gov. Retrieved 2011-11-08. 5. ^ a b Dendy, P. P.; B. Heaton (1999). Physics for Diagnostic Radiology. USA: CRC Press. p. 12.ISBN 0750305916. 6. ^ Charles Hodgman, Ed. (1961). CRC Handbook of Chemistry and Physics, 44th Ed.. USA: Chemical Rubber Co.. p. 2850. 7. ^ Feynman, Richard; Robert Leighton, Matthew Sands (1963). The Feynman Lectures on Physics, Vol.1. USA: Addison-Wesley. pp. 2–5. ISBN 0201021161. 8. ^ L 'Annunziata, Michael; Mohammad Baradei (2003).Handbook of Radioactivity Analysis. Academic Press. p. 58. ISBN 0124366031. 9. ^ Grupen, Claus; G. Cowan, S. D. Eidelman, T. Stroh (2005). Astroparticle Physics. Springer. p. 109.