Health Physics: Using the Spectrum

• a very intense beam of light that carries a great deal of energy
• can cut through human body tissue and seals blood vessels

• medicine, for: eye surgery
• removal of birthmarks
• removal of cancerous tumours

can be used to find broken bones

• a beam of x-rays is aimed at the patient
• since bones is more dense than the surrounding tissue it absorbs more x-rays
• a shadow is cast on the photographic film placed behind the patient
• the x-rays blacken the film, so the bones show up white and any breaks as dark lines

• a series of horizontal x-ray images are taken of the body
• a computer then uses these slices to build up a 3-D image of the body
• this enables small tumours to be found very accurately and provides more detailed images than conventional x-ray pictures

simply heat radiation with a wavelength longer than that of visible light

to speed up the recovery of injured muscles and tissues

• radiation with a wavelength shorter than that of visible light
• excessive exposure can cause skin cancer

infrared radiation is used in a thermal imagingcamera where object at different colours on a picture