basic concepts how much do you already know?.???questions??? n matter n occupies_____________ n is a...

BASIC CONCEPTS

How much do you already know?

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MATTER Occupies_____________ is a material substance Has________and shape Building blocks of matter are_______and

__________.

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MATTER The primary characteristic of matter is

_____________ Mass is the quantity or quality of an object? ANSWER…QUANTITY Does mass change when matter changes? Give an example of a change of matter.

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WEIGHT is the mass of matter in an object in ?

Why do we weigh less on the moon

than on earth?

Types of energy (joules or eV)

Potential Kinetic Chemical Electrical Thermal Nuclear Electromagnetic

RADIATION

ENERGY EMITTED AND TRANSFERRED THROUGH SPACE

PIANO STRING=RADIATE SOUND RIPPLES OR WAVES=WAVES

RADIATE

IONIZING RADIATION(AGAIN!!!)

Removes orbital electron from atom this electron can disrupt surrounding atoms

by transferring energy to them. This renegade(free) electron- negative ion The atom that lost the electron- positive ion negative ion & positive ion = ion pair

What two forms of electromagnetic radiation ionize matter?

X-rays

Gamma rays

What two particulate forms of radiation ionize matter?

alpha

beta

SOURCES OF RADIATION HARMFUL TO HUMANS Natural

– Cosmic

– Terrestrial

– Naturally occurring radionucleides in the human body

Manmade– medical x-rays– nuclear power plants– industrial sources– watch dials*– smoke detectors*– TV*– Airport surveillance

systems*

DID YOU KNOW?

Naturally + man-made radiation occurring radiation contributes 360 mrads to the average absorbed dose to humans.

Diagnostic x-rays make up the largest source of man-made radiation (39 mrem per year-50 mrem per year)

IN THE EARLY YEARS OF USING X-RAYS Skin damage (erythema) loss of hair (alopecia) low red blood cell counts(anemia)

INJURIES DUE TO low energy radiation looooonnnngggg exposure times

(30 minutes!!!!!!!!!!!!!!!)

REDUCTION TO RADIATION EXPOSURE

Coolidge tube (Hot-cathode x-ray tube)–vacuum tube–intensity and energy to be selected (1913)

Snook transformer

High voltage power, induction coils (1910)

Potter-bucky grid (1921)

PROTECTIVE APPAREL WAS DEVELOPED WHEN IT WAS NOTED THAT RADIOLOGISTS WERE DEVELOPING AT A HIGH RATE OF LEUKEMIA AND APLASTIC ANEMIA

Effects of radiation

Early

blood changes

decreased sperm count

Latent

cancer changes

possible genetic effects

REGULATION HISTORY

1966- ICRP developed

ALARA

Radiation must have a benefit

Dose should not exceed limits for specific circumstances

REGULATION HISTORY

1987- NCRP established

limits for radiation exposures for radiation workers and non-radiation workers

limits were to minimize potential harm

CARDINAL PRINCIPLES OF RADIATION PROTECTION

TDS

DEVICES FOR MINIMIZING RADIATION TO PT/WORKER

Filtration collimation Intensifying screen Protective barriers Protective apparel Technical factors (Highest optimal kVp,

shortest time)

“The risk of radiation exposure in diagnostic imaging departments is minimal. Radiography is now considered a radiation safe occupation.”RADIOLOGIC SCIENCE FOR TECHNOLOGISTS,Stewart Bushong, 1997Page 7