BASIC CONCEPTS - Montgomery College
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Transcript BASIC CONCEPTS - Montgomery College
BASIC CONCEPTS
How much do you already know?
????QUESTIONS???
MATTER
Occupies_____________
is a material substance
Has________and shape
Building blocks of matter are_______and
__________.
????QUESTIONS???
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.
????QUESTIONS???
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
Manmade
–
–
–
Terrestrial
–
–
–
Naturally occurring
radionucleides in the
human body
–
–
–
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)
EVOLVE
Module 1: Introduction to Radiographic
Equipment
https://evolve.elsevier.com/cs/Satellite/Stu
dentHome?Audience=Student
Homework
Section 2: Overview of Discovery and Use
of X-Rays Quiz link.
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
T
D
S
DEVICES FOR MINIMIZING
RADIATION TO PT/WORKER
Filtration
collimation
Intensifying screen
Protective barriers
Protective apparel
Technical factors (Highest optimal kVp,
shortest time)
CLOSE YOUR BOOKS
PLEASE
“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, 1997
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