ELECTROMAGNETIC RADIATION

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ELECTROMAGNETIC RADIATION
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NOVEMBER 8, 1895 ROENTGEN DISCOVERED X-RAYS IN
HIS LAB IN WURZBURG GERMANY
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ROENTGEN EXPERIMENTED WITH CATHODE RAYS USING THE
CROOKES TUBE
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PHOTONS ARE ENERGY DISTURBANCES MOVING THROUGH
THE SPACE WITH THE SPEED OF LIGHT (C)
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PHOTONS HAVE NO MASS AND NO CHARGE. THEY HAVE
MAGNETIC AND ELECTRIC FIELDS CHANGING IN
SINUSOIDAL FASHION
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SPEED OF LIGHT

• 3 x 10 8 m/s
• 3 x 10 5 km/s
• 300,000 km/s
• 186,400 miles/s

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GAMMA vs X-RAYS
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GAMMA EMISSION
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X-RAYS EMISSION
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THREE WAVE PARAMETERS ARE NEEDED TO DESCRIBE
ELECTROMAGNETIC RADIATIONVELOCITY, WAVELENGTH,
AND FREQUENCY
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ELECTROMAGNETIC WAVE EQUATION

• CF x ?

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ELECTROMAGNETIC SPECTRUM
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(No Transcript)
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THE ENERGY OF PHOTON IS DIRECTLY PROPORTIONAL TO
ITS FREQUENCY
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THE ONLY DIFFERENCE BETWEEN X-RAYS AND GAMMA RAYS
IS THEIR ORIGIN
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VISIBLE LIGHT IS IDENTIFIED BY

• WAVELENGTH

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RF IS IDENTIFIED BY

• FREQUENCY

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X-RAYS ARE IDENTIFIED BY

• ENERGY

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X-RAYS BEHAVE AS THEY ARE PARTICLES
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PROPERTIES OF X-RAYS

• HIGHLY PENETRATING, INVISIBLE RAYS
• ELECTRICALLY NEUTRAL
• POLYENERGETIC
• LIBERATE MINUTE AMOUNTS OF HEAT ON PASSING
  THROUGH MATTER
• TRAVEL ORDINARILY IN STRAIGHT LINES
• TRAVEL WITH THE SPEED OF LIGHT
• IONIZE GASES INDIRECTLY
• CAUSE FLUORESCENSE OF CERTAIN CRYSTALS
• CANNOT BE FOCUSED BY LENS
• AFFECT PHOTOGRAPHIC FILM
• PRODUCE CHEMICAL AND BIOLOGICAL CHANGES
• PRODUCE SECONDARY AND SCATTER RADIATION

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RADIATION ATTENUATION IS THE REDUCTION IN
INTENSITY RESULTING FROM SCATTERING AND ABSORPTION
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STRUCTURES THAT ABSORB X-RAYS ARE CALLED

• RADIOPAQUE ????

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STRUCTURES THAT ATTENUATE X-RAYS ARE CALLED

• RADIOLUCENT ??

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INVERSE SQUARE LAW
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INVERSE SQUARE LAW FORMULA
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(No Transcript)