ELECTROMAGNETIC RADIATION

PHOTONS ARE ENERGY DISTURBANCES MOVING

THROUGH THE SPACE WITH THE SPEED OF LIGHT (c)

PHOTONS HAVE NO MASS AND NO CHARGE. THEY HAVE MAGNETIC

AND ELECTRIC FIELDS CHANGING IN SINUSOIDAL FASHION

CHARACTERISTICS OF X-RAY PHOTONS

1. Highly penetrating, invisible rays, more penetrating than Alpha and Beta radiations.

2. Electrically neutral. They do not get attracted to charged electrodes.3. Polyenergetic. X-ray beam represent the wide range of different photon

energies, with the maximum energy photons indicated by the kVp setting.4. Release small amounts  of thermal energy when they pass through

matter. 5. Travel in straight lines. 6. Travel with the speed of light in vacuum. 7. Ionize matter by removing orbital electrons. 8. Induce fluorescense in some substances. 9. Can't be focused by lenses nor by collimators. 10. Produce chemical and biological changes 11. Produce scatter radiation

           

Highly penetrating, invisible rays, more penetrating than Alpha and Beta radiations

Electrically neutral. They do not get attracted to charged electrodes

Travel in straight lines

Travel with the speed of light in vacuum.

• 3 x 10 8 m/s•

3 x 10 5 km/s

• 186,400 miles/sec

Ionize matter by removing orbital electrons

Induce fluorescense in some substances

Produce scatter radiation

PRODUCTION OF ELECTROMAGNETIC RADIATION

X-RAYS

GAMMA RADIATION IN THE UNIVERSE

XMM-NEWTON SATELLITE UNCOVERS DIFFUSE X-RAY EMISSION AND THE FIRST ACCRETING X-RAY PULSAR IN ANDROMEDA GALAXY

GAMMA vs X-RAYS

GAMMA EMISSION

Electron cloud in the target

X-RAYS EMISSION

THREE WAVE PARAMETERS ARE NEEDED TO DESCRIBE

ELECTROMAGNETIC RADIATION:

VELOCITY, WAVELENGTH, AND FREQUENCY

ELECTROMAGNETIC WAVE EQUATION

c = f x Λ

ELECTROMAGNETIC SPECTRUM

Short wavelength

High frequency High energy

Long wavelength Low frequency

Low energy

THE ENERGY OF PHOTON IS DIRECTLY PROPORTIONAL

TO ITS FREQUENCY

THE ONLY DIFFERENCE BETWEEN X-RAYS AND GAMMA RAYS IS THEIR

ORIGIN

VISIBLE LIGHT IS IDENTIFIED BY:

• WAVELENGTH

RF IS IDENTIFIED BY:

• FREQUENCY

X-RAYS ARE IDENTIFIED BY:

• ENERGY

X-RAYS BEHAVE AS THEY ARE PARTICLES

RADIATION ATTENUATION IS THE REDUCTION IN

INTENSITY RESULTING FROM SCATTERING AND

ABSORPTION

STRUCTURES THAT ABSORB X-RAYS ARE CALLED

• RADIOPAQUE ????

STRUCTURES THAT ATTENUATE X-RAYS ARE

CALLEDRADIOLUCENT ??

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