NDI Unit 9-1-1-1

What is the electromagnetic spectrum?

A scale comparing X-rays to other electromagnetic waves such as infrared, ultraviolet, RF (radio frequency) in respect to energy and wavelengths of each

What is an atomic structure?

An atom containing a positively charged nucleus and one or more negatively charged electrons.

What is a wavelength?

Distance on a wave from one point to the next corresponding point (EX. crest to crest)

What are the characteristics of X-rays?

-Atomic Structure -Electromagnetic Spectrum -Production of X-Rays

What are the advantages of radiography?

-Increased safety of equipment -Provides permanent digital records on file -Can be used on virtually any materials -Minimal disassembly required -Provides an internal view of the condition of parts, components and structural make up

What are the general applications of radiography?

-Medical (first used in 1920's, lack of knowledge limited its use) -Rocket Fuels -Used by civilian industry in 1930's for QA (quality control) -Aircraft related maintenance radiographs -Commercial airlines developed techniques for aircraft in 1950 -The armed forces adopted these techniques in 1958 for missiles, ships, ammunition, aircraft and related equipment

What are the disadvantages of radiography?

-Radiation exposure hazard -Extreme degree of skill required -High cost -Defect must be properly oriented -Intensive training is required (must be trained in safety and operations)

What are the three basic requirements for the production of X-rays?

-Source of electrons -Acceleration or movement of electrons -Sudden Stop

What is the range (in angstroms) for X-rays and Gamma rays?

.01 to 1,000 angstroms

How many inches in 1 cm?

.394 inches

How many cm is one angstrom?

10 to the negative 8th power (cm) or .00000001 (cm)

What year was radiography founded?

1895

In the production of a photon of energy, what percent of energy involved is X-rays?

3%

In the production of a photon of energy, what percent of energy involved is heat?

97%

What is radiography?

A non-destructive testing method where a source of X-rays or gamma rays are utilized to indicate the subsurface condition of opaque materials.

What is a radiograph?

A permanent record of the soundness characteristics made on a specially prepared instrument plate

Is an X-ray a photon or a quanta?

An X-ray is a photon, or quanta (small bundle of energy)

What unit of measurement is used for measuring wavelengths?

Angstroms

How many kV are normally present in characteristic interaction?

Below 100kV (they are low energy X-rays)

What are the two forms of interaction?

Characteristic and Continuous

What metal's atomic structure is most used for artificially releasing energy and why?

Cobalt's atomic structure is most used because the energy it releases is a very penetrating form of gamma waves

What is ionization?

Completely removes an electron from an atom

What may the electron do after the first continuous interaction?

Continue to travel and interact again.

Which piece of an atomic structure spin on their axis, orbit the nucleus and has specific energy momentum, weight and tracks?

Electrons

An X-ray beam is what:

Heterogeneous

How are electrons arranged around the nucleus in an atomic structure?

In a circular or elliptical path.

Which electron shell is located closest to the nucleus?

K shell

Which electron shell is the weakest (has lowest energy level)?

K shell

What range of letters are used to identify the layers of electron shells?

K through Q

What holds the electrons in their shells?

Kinetic energy and centrifugal force

Many atomic structures can be artificially made to release energy by subjecting them to strong fields of _________

Neutrons

What are electron shells?

Orbit of electrons

How many kV are normally present in continuous interaction?

Over 100 kV (High energy X-rays)

What is monochromatic?

Single wavelength one electron shell interacts on

What is atomic (mass) weight (A)?

The approximate total mass of the nucleus (Number of protons and neutrons)

What is Frequency?

The number of waves that pass a given in a given amount of time.

Energy emitted in a characteristic interaction is dependent on what?

The velocity of the electron and the energy level of the electron struck.

What happens with electrons that do not produce X-rays during the production of a photon of energy?

They are converted into heat

What is the atomic number (Z)

Total number of protons in a stable atom (same number of electrons)

Due to different interactions different ______________ are produced

Wavelengths

How is a photon of energy produced?

When a high velocity electron strikes a material and interacts with its atomic structure

What is continuous interaction?

When a travelling electron interacts with a nuclear field. The nuclear field slows the electron and the energy is converted into X-rays.

What is Characteristic interaction?

When incident electron strikes an inner shell electron (electron to electron interaction)

Who is the founder of radiography?

Wilhelm Röntgen

What type of charge does an electron have

negative

What type of charge does a neutron have?

no charge/neutral

What type of charge does a proton have?

positive