Chapter 2 RADR 1313

What portion of the x-ray tube contains the filament?

Cathode

What is the cathode filament made of?

Tungsten

What type of charge does the focusing cup have?

Negative charge

In a dual-focus tube, how many filaments are energized at one time?

One

What is the focusing cup made of?

Nickel

What phenomenon occurs around the filament during thermionic emission and prevents further electron escape?

Space charge effect

What is the positive side of the x-ray tube?

Anode

What is the maximum typical speed of a rotating anode?

10,000 rpm

What is the base material of the anode disk?

Molybdenum and graphite

What is the fixed physical area on the anode target struck by electrons called?

Focal spot

What device turns the rotor in a rotating anode x-ray tube?

Stator

What is the acceptable level of leakage from the tube housing?

1 mGy/hour at 1 meter

What is the purpose of an x-ray circuit design?

Produce a predictable x-ray beam

What must electrons do to perform work in a circuit?

Flow in a circuit

What is the non-conductive oil surrounding the x-ray tube called?

Dielectric

What does the anode spin around in a rotating anode x-ray tube?

Central axis

What is the boiling off of electrons from the filament called?

Thermionic emission

What is the flow of electrons from cathode to anode called?

Tube current

What does milliamperage (mA) measure?

Current

What unit expresses electrical power?

Watts (W)

What is a key advantage of higher-kW x-ray generators?

Shorter exposure times at higher techniques

What does the primary side of the x-ray circuit do?

take incoming voltage and increase to kilovoltage

What device primarily regulates and controls voltage in electrical circuits?

Transformers

What device nearly surrounds the filament?

Focusing cup

How many cathode filaments does a dual-focus tube have?

Two

What is the rotating anode target track primarily made of?

Tungsten

What is the typical range of rotating anode target angles?

5° to 20°

What is the relationship between tungsten's atomic number and melting point?

Direct

What part is connected to the anode target and causes it to turn?

Rotor

What is an advantage of having a focal track?

Higher exposure factors can be used

What type of x-ray tube envelope is more commonly used today?

Metal

What is an advantage of a metal envelope compared with glass?

Decreased off-focus radiation

What is found inside the x-ray tube envelope?

Vacuum

What device creates the induced voltage supplied to the primary side of the high-tension transformer?

Autotransformer

What is the typical diagnostic x-ray exposure range?

50 to 150 kVp

What do resistors primarily control in an electrical circuit?

Amperage

What do higher mA levels during exposure permit?

Shorter exposure times

What circuit components allow electrons to flow in only one direction?

Diodes

What unit expresses the electrical power of x-ray machines?

Kilowatts (kW)

What are the benefits of high-frequency x-ray generators?

All of the above

The x-ray tube is an example of electron flow in what environment?

Vacuum

What allows precise flow and intensity of electrons along designed pathways?

Circuits

What principle do transformers operate on?

Mutual induction

How is kVp selection achieved in an x-ray generator?

Autotransformers

What is Vs/Vp = Ns/Np called?

Transformer Law

What primarily regulates and creates voltage values in a circuit?

Transformers

As voltage increases in a transformer, what happens to amperage?

Decreases proportionally

What must the current through an x-ray tube be converted to?

DC

How is approximately 1% voltage ripple achieved in modern x-ray generators?

High-frequency inverters

What do safety circuit components control?

All of the above

What circuit components store electrical charge and can create a high-frequency waveform?

Capacitors

Can electrons flow from anode to cathode during x-ray exposure?

False

Do resistors primarily control the amount of current flowing through a circuit?

True

Are capacitors designed to store electrical charge in circuits?

True

Can circuit components momentarily withstand high voltage because x-ray production uses short exposures and low mA?

True

Does the “Ready Light” indicate that everyone is at a safe distance from the x-ray source?

False