X-rays were first observed anddocumented in 1895 by German
scientistWilhelm Conrad Roentgen. He discoveredthat firing streams
of x-rays through armsand hands created detailed images of thebones
inside. When you get an x-raytaken, x-ray sensitive film is put on
one sideof your body, and x-rays are shot throughyou. Because bones
are dense and
absorb more x-rays than skin does,shadows of the bones are left
on the x-rayfilm while the skin appears transparent.
8/12/2019 Handout Xray and Gamma Ray
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X-rays for medical diagnostic
procedures / research purposes Produced by accelerating
__________ with high voltage
and allowing them to collide with a metal target
Produced when electrons suddenly ______________
upon collision with the metal target
Voltage used in X-raystube
Frequency of X-raysproduced
Application
4 MV 1021 Hz
1020Hz Inspection of cracks inengine body
70 kV 1.7 x 1019Hz
5 x 1018Hz Treatment of skindiseases
8/12/2019 Handout Xray and Gamma Ray
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GAMMA RAYSGamma rays (_________) r emitted fr
nucleus of unstable (_____________) atoms
-- generated by nuclear decay
Highest __ (>1020Hz)
Smallest __ (< 10-12m )
Highest ___Can kill living cells
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Radionuclides / sources ofgamma rays Medical treatment
Cesium-137
Treat cancer, sterilise medicalequipment
Technetium-99m Diagnostic studies and imagingof body organs
* Material x become radioactive when irradiated by GR
