Ionizing Radiation Flashcards
What is a “Coulomb” or a “Roentgen”?
Coulomb or Roentgen is the measure of
transfer of energy & resulting ionization.
Who discovered X-Rays and when did this happen?
William Roentgen discovered X-Rays in 1895.
Who discovered Gamma Rays and when?
Marie and Pierre Curie discovered Gamma Rays in the late-1800s.
What do X-Rays and Gamma Rays have in common?
They are both forms of electromagnetic wave radiation
with enough energy to ionize.
What do Radio, TV, Radar, Infra-Red, Visible Light, Ultra-Violet and Micro electromagnetic energy waves have in common?
They do not have enough energy to ionize atoms they encounter.
(They don’t have the energy to remove electrons from those atoms.)
What is the Atomic Number (Z) referring to?
Atomic Number (Z) = the number of protons in the nucleus of an atom.
What is the Mass Number (A) referring to?
Mass Number (A) = total of protons & neutrons in the nucleus of an atom.
N = (A) - (Z)
eg. Uranium 238 has a mass number (A) of 238 and an atomic number (Z) of 92, therefore the number of neutrons will be: 146
What is Coulomb’s Law?
Coulomb’s Law states that this is the binding energy or attraction force which is greater the closer the electrons in orbit are to the nucleus.
This same binding energy decreases as the electron shells move away from the nucleus.
What can X-Ray radiation produce with its ionizing effects?
- can cause certain material to fluoresce
- can produce chemical effects
- can cause biological effects (eg. deterioration of living cells)
- gasses bombarded by radiation can become electrical conductors (eg. ionization detectors)
X-Rays and Gamma Ray radiation share properties that are important to know. What are they?
- they travel in straight lines
- they are not affected by electrical or magnetic fields
- they cannot be focussed
- they affect photographic chemical emulsions
- they damage or destroy living cells, produce burns and can produce changes to blood or blood-forming organs
- they cannot be detected by human senses
What are some characteristics of an Alpha (⍺) radiation particle?
- they are large & slow moving
- they quickly give up their energy
- they cause ionizations along a short path
- they cannot penetrate a layer of dead skin
- they are most hazardous when they are ingested or inhaled
What are some characteristics of a Beta (β) radiation particle?
- they are very light and fast moving
- they have an electrical charge of -1
- they are easily deflected & scatter as they pass through matter
- they can be absorbed by a few mm of aluminum
- they can travel a few hundred cm before losing energy
What are some characteristics of Neutron (n) radiation particles?
- they are not normally emitted during the natural decay process
- they have the same mass as a proton
- they no electrical charge
- spontaneous emission can occur without the interaction of a photon
- they are best shielded against by water
What is RAD or Radiation Absorbed Dose?
How is it now measured?
RAD is the quantity for
RAdiation Damage in living tissue.
It is now measured in Grays (Gy)
which is defined as 1 Joule of energy absorbed
per kg of tissue mass.
1 RAD = 10 mGy
1 GRAY = 100 RADs
What is another name for REM?
Dose Equivalent