Periapical xray

Component parts, X-ray tube, X-ray generating machine

Control Panel, Extension Arm, Tubehead

on-off switch and an indicator light, Exposure button and indicator light, Control devices - regulate the x- ray beam

Exposure Time, Kilovoltage, Milliamperage selectors

Suspends the x-ray tubehead, Houses the electrical wires that extend from the control panel to the tubehead, Allows for movement and positioning of the tubehead

Tubehead

metal body of the tubehead, Surrounds the x-ray tube and transformers, Filled with oil, Protects the x-ray tube, G ro u n d s t h e h i g h - voltage components

Oil that surrounds the x-ray tube and transformers inside the tubehead., Prevents overheating by absorbing the heat created by the production of x-rays.

Aluminum or leaded glass covering of the tubehead that permits the exit of r a d i a t i o n f r o m t h e tubehead., Seals the oil in the tubehead and acts as a filter of the x- ray beam.

H e a r t o f t h e x - r a y generating system, Cathode, Anode

A device that alters the v o l t a g e o f i n c o m i n g electricity., Increase or decrease the voltage in an electrical circuit.

filament circuit, Used to decrease the voltage from the incoming 110 to 220 line voltage to the 3 to 5 required., Has more wire coils in the primary coil than in the secondary coil.

primary coil

output coil

high voltage circuit–use to increase the voltage from the incoming 110 or 220 line voltage to the 65,000 to 100,000 volts required, Has more wire coils in the secondary coil than in the primary coil.

Autotransformer

Sheets of 0.5 mm thick aluminum placed in the path of the x-ray beam., f i l t e r o u t t h e n o n p e n e t r a t i n g l o n g e r wavelength x-rays.

Lead plate with a central hole that fits directly over the opening of the metal housing where the x-rays exit., Restricts the size of the x- ray beam.

O p e n - e n d e d , l e a d l i n e d cylinder that extends from the opening of metal housing of the tubehead, Aims and shapes the x-ray beam, 8, 12, 16 inches long, Sometimes referred to as the cone

glass vacuum tube in which all of the air has been removed, Electrons produced in the n e g a t i v e c a t h o d e a r e accelerated in the positive anode, Leaded glass housing, Cathode, Anode

Leaded glass vacuum tube that prevents x-rays from escaping in all directions, Has a window that permits, The x-ray beam to exit the tube, Directs the x-ray beam towards the aluminum disks, lead collimator and PID

Cathode

Anode

supply the electrons necessary to generate the x-rays, Negative electrode, Tungsten filament, Molybdenum cup

Tungsten filament

Molybdenum cup

Positive electrode, Convert electrons into the x-ray photons, Tungsten target, Copper stem

Tungsten target

Copper stem

High atomic number, High melting point, Low vapor pressure

Electricity and electric current, Electrical circuits, Transformers

Electricity

Electrical energy

Electric current

AMPERAGE

Amperes or milliamperes

VOLTAGE

Volts or kilovolts

Milliamperage (mA) adjustment

Kilovoltage peak (kVp) adjustment-

Circuit

( low voltage), uses 3 to 5 volts, Controlled by the milliamperage

High voltage circuit

current ( 110 – 220)

transformer

3 to 5 volts

Thermionic emission

Bremsstrahlung, Radiation produced when the speeding electrons slow down because of their interactions with the tungsten target in the anode., 70% of x- ray energy produced at the anode., Consists of x-rays of many different energies and wavelengths.

Direct hit, Near miss

Direct Hit

Electron doesn’t hit the nucleus, Electron is attracted towards (+) charged nucleus, The passage of electrons near the nucleus, which results in electrons being deflected and decelerated.

P r i m a r y X-radiation

Secondary X-radiation