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8/14/2019 Radiation Safety Series 1
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Radiation Safety SeriesLesson 1
Introduction to Radiation
Discovery of Radioactivity
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History of Discovery
1895 Wilhelm Roentgen; Discovered X-Ray
1895 Henri Becquerel; Rays from Uranium
1898 Marie & Pierre Curie; Work withRadium
1899 Ernest Rutherford; Alpha, Beta &Gamma
1905 Albert Einstein; Theory of Relativity
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Wilhelm Roentgen
8 Nov 1895Discovered X-Rays
Received the NobelPrize in Physics 1901
Brilliant Scientist
Never sought Honorsor profit from his work
www.accessexcellence.org/AE/AEC/CC/radioactivity.html
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Henri Becquerel
Third GenerationScientist
DiscoveredRadioactivity
Discovered chargedpartials.
Received the NobelPrize in Physics 1903
www.accessexcellence.org/AE/AEC/CC/radioactivity.html
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Marie & Pierre Curie
Marie coined the termRadioactivity
Both discoveredPolonium & Radium Both shared the Nobel
Prize in Physics of
1903 1910 Curie is basicunit of radioactivity
www.accessexcellence.org/AE/AEC/CC/radioactivity.html
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Ernest Rutherford
The father of nuclearphysics
Particles- Alpha, Beta& Neutron Radioactive decay
equation
Concept of half life Elements transmuted 1908 Nobel Price
www.accessexcellence.org/AE/AEC/CC/radioactivity.html
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Albert Einstein
General physicist Most well-known
physicist of our time E = mc2 Theoretical indication
that the Atomic Bombis possible
www.bartleby.com/173/
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Milestones in Radiation and
Radiography1922 Memorial to scientists in Hamburg Germany
1922 Industrial X-Ray; Watertown Laboratory
1929 Gamma Radiography; Naval Research Lab.1945 1st Atomic Bomb; White Sands Missile
Range
1946 Atomic Energy Commission EstablishedRadiation Safety Training Series Part 1: Radiation, Rudarmel Enterprises, inc. Lake Oswego, Oregon
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Atoms are Elements
Elements are made of Electrons
ProtonsNeutrons +, positive charge -, negative charge
0, neutral charge
Radiation Safety Training Series Part 1: Radiation, Rudarmel Enterprises, inc. Lake Oswego, Oregon
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SHELLS ONLY HOLD SOME
ELECTRONS The first 18 elements k-shell only holds two
l-shell only holds eight m-shell only holds eight m-shell can actually hold
up to 18 electrons as you
move further along theperiodic table.Radiation Safety Training Series Part 1: Radiation, Rudarmel Enterprises, inc. Lake Oswego, Oregon
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ORBITAL BASICS
A shell is sometimescalled an orbital orenergy level.
Shells are areas thatsurround the center of anatom.
The center of the atom is
called the nucleus. Electrons live in
something called shells.Radiation Safety Training Series Part 1: Radiation, Rudarmel Enterprises, inc. Lake Oswego, Oregon
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Mathematical Probability
Orbitals are describedby probability
An orbital exists as acloud Each atom has a
different orbital cloudstructure
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch6/quantum.html
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www.mii.org
http://www.smartdraw.com/resources/examples/science/images/periodic_table_full.gifhttp://www.smartdraw.com/resources/examples/science/images/periodic_table_full.gifhttp://www.smartdraw.com/resources/examples/science/images/periodic_table_full.gifhttp://www.smartdraw.com/resources/examples/science/images/periodic_table_full.gif8/14/2019 Radiation Safety Series 1
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Element Description
Atomic number 6 Atomic mass 12.01
Electron configuration Oxidation state Symbol
Melting/boiling point Density/electronegativ
ity
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Isotopes
Hydrogen is thecommon stable form
Deuterium is rare butstable form Tritium (radioactive)
is an unstable form
Atoms of the sameelement have differentcharacteristics
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Origin and Types of Radiation
Bremsstrahlung braking ray
-high energy electron impacting a target
Nuclear decay Manmade radioactivity
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Simple X-Ray Generator
Electrons boiled offthe cathode
Electrons impact theAnode -dense material A continuous
spectrum of X-Raysare emitted in alldirections
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Radiation from Nuclear Decay
Collimated radiation One spot would glow
Magnetic field wouldmake three spots glow
- Alpha
- Beta- Gamma
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Types of Radiation
Alpha partial is two protons and twoneutrons having a positive charge and mass
Beta particle is a high energy electron witha negative charge and little mass Gamma ray is electromagnetic energy
possessing no mass and no charge Neutron particle has no charge but it doeshave mass
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Electromagnetic Spectra
www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html
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Differences in Gamma and X-ray
X-Ray wavelengths ranges 10-8 to 10-13 Gamma wavelength ranges 10-11 to 10-13
X-Ray is electronically generated and stopswhen you turn off the power
Gamma is naturally occurring andcontinuous
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Human Exposure to Radiation
Exposure from Manmade Sources
Medical (mostly diagnostic x-ray) 45%
Fallout from atomic bombs 2.5%Nuclear power 0.15%
Consumer products (mostly color TVs) 0.5%
Approx. % annual exposure 50%
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Human Exposure to Radiation
Occupational Radiation exposures
Workers at Gamma Radiography
Companys 3XGamma radiographers 5X
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Time, Distance and Shielding
How do we reduce our exposure toradiation?
We can calculate stay times, dose rates anddistance from sources.
We can calculate shielding requirements
and or effects Our first step, Inverse Square Law
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Inverse Square Law, General
Continued Being strictly geometric in its origin, the
inverse square law applies to diverse
phenomena. Point sources of gravitationalforce, electric field, light, sound or radiationobey the inverse square law.
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Inverse Square Law, Radiation
http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html
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Inverse Square Law, Radiation
S/4r2 = I
S = 4r2 I
S = 4r12 I1S = 4r2
2 I24r1
2 I1 = S = 4r22 I2
4r12 I1 = 4r22 I2
r12 I
1= r
22 I
2
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Example
If the intensity of the Andrex is 1040 R/hr atone foot from the tube head then what is the
distance to the 2mR line.I1 = 1040 R/hr r 1 = 1
I2 = 2 mR/hr r 2 = ?
r12 I1 = r2
2 I2 r2 = (r12 I1/ I2)
r2 = (r12 I1/ I2)
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Example
r2 = (r12 I1/ I2)
r2 = (1040 R/hr 1 / 0.002 R/hr)
r2 = 721
r2 = 721 feet
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Works SitedPartial List:
http://www.accessexcellence.org/AE/AEC/CC/radioactivity.html
http://www.accessexcellence.org/AE/AEC/CC/historical_background.html
Radiation Safety Training Series Part 1: Radiation, Rudarmel Enterprises, inc.Lake Oswego, Oregon
http://www.chem4kids.com/files/atom_structure.html
http://orbitals.com/orb/
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch6/quantum.html
www.bartleby.com/173/
www.mii.org
http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html