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N5 Waves & Radiation

Created by Mr. Twentyman

N5 Waves & Radiation

Shielding & Protection

Time

Distance

Shielding materials ( + PPE, tools)

All to minimise exposure

Half Life

Time for activity of substance to decrease by a half

Corrected count rate plotted against time --> decay curve --> Half life

Electromagnetic Spectrum

All travel at 3 x 108ms-1

R, M, I, V, U, X, G

Detectors

Hazards

Industrial and Medical Application

Wave Speed

v = f x wavelength (lambda)

measure in ms-1

d = v x t

Medical Applications

Radio isotope tracers

Instrument sterilization

Radio therapy - cancer treatment

Types of Radiation

ALPHA

Beta

Gamma

Unique properties

Dist travel in Air

Penetration

Mass (AMU)

Charge

Ionisation Density

Deflection in fields

 

Wave Properties

Transfer Energy

Longitudinal - sound

Transverse - everything else

Wavelength

Amplitude (Energy)

Wavespeed

Applications

Industrial - Power Generation, Non destructive testing, e.g. pipe welds; Process control - thickness monitoring

Medical

Activity

Number of atomic nuclei decays per second

A = N/t

Measured in Bequerels

Speed of Sound in Materials

Air

Solids & Liquids

340ms-1 in air

 

Industrial Applications

NDT

Pipe Weld checking

Process control

Radiation

Isotopes

Ions

Mass and Atomic Number

Energy Instability

Waves

Oscilloscope to see waves

Repeating oscillation/vibration

Frequency

Number of Waves per second

Fission

Spontaneous Fission

Induced Fission

Chain Reaction

Power Generation

Ionisation Detectors

Geiger Muller Tube & Counter

Film Badge

Scintillation Counter

Spark Gap 

Cloud Chamber

N5 Waves & Radiation Unit

Diffraction

Wavelength to diffraction link

Gaps and barriers

X ray diffraction

Radio reception in hilly areas cf TV reception

Period

No of seconds per wave (T)

measured in seconds

f + 1/T   and T = 1/f

Ionisation

Production of Ion

"Addition or loss of an electron from an atom resulting in a positive or negatively charged ion"

Ionisation density link to Types

Nuclear Power Station

Reactor Core containing

Fuel Rods - U235 and U238

Control Rods - Boron to absorb surplus neutrons

Moderator to slow neutrons to thermal (slow) speeds

Coolant to move heat to boiler/heat exchanger

All contained within Containment vessel

Fusion

Small nuclei (Hydrogen) fusing to make Helium.

Very high temperature and pressure = engineering challenges

Mass difference = energy produced

Dosimetry

Refraction of Light

Speed change possibly showing up as direction change.

Normal line for angle measuring

Optical density

Equivalent Dose

H = D x WR

H = Equivalent Dose measure in Sieverts (Sv)

D = Absorbed Dose (Gy)

WR = radiation weighting factor (no units) dependant on type of radiation

Lenses & Prisms

Focal point and focal length

Determining the focal length of convex lens

Dispersion of white light via prism

Absorbed Dose

Absorbed Dose (D) = Energy (E)/Unit Mass (m)

1 Gray = 1 Joule / 1 kilogram

Measured in Grays

Background Radiation

Sources - natural and man-made/artificial

N4 Sound

Range of human hearing

Infra sound & Ultrasound

Longitudinal wave requiring particles for energ transfer

Speed of Sound in Air/Liquids/Solids

Experiment to measure

340 ms-1

Echo problems!

Sound in a Vacuum!

Annual Equivalent Dose Limits

1 mSv public

20 mSv radiation industry worker

Equivalent Dose Rate

H Dot = H/t

Sieverts per second/minute/hour/year/etc.

Applications

Ultrasound scanning

Depth finder

SONAR

Sound Levels

Decibels (dB)

Range of examples

 

Sound Reduction & Protection

Ear defenders

Ear Plugs

Noise cancelling headphones  - inverted sound