Unit 1&2 Flashcards
(29 cards)
What charge is on the cathode end of the tube?
negative
What are the two main parts of the cathode?
filament and focusing cup
What is the main filament maid of?
Tungsten
What is the source of electrons in xray production?
Filament
What charge is on the focusing cup?
Negative to repel negatively charged electrons
What is the space charge effect?
As more electrons build up, their negative charge opposes emission of more electrons
What is the focusing cup made of?
Nickel
Thermionic Emission?
Process of boiling off electrons
What are the three main parts of the anode?
Motor, stator, rotor
Maximum MA & KVP?
600 MA, 150 KVP
What is the source of xrays?
Anode
What is the stationary anode made of?
Copper w tungsten target
Why do we spin the anode?
to dissipate heat
What action do you do to start the anode spinning?
Rotor
What is the only part outside of the glass envelope?
Stator
What is the portion of the envelope called where xrays leave the tube?
The window
What is the maximum housing leakage allowed?
1 mGy/hr @ 1 meter
Progression of image receptors in xray history?
Glass plate>cellulose nitrate>polyester film>digital/CR>DR
What is meant by electromagnetic radiation?
Not a particle >It’s a wavelength frequency - moves at speed of light
What happens when you rotor?
You’re applying (MA)x(S) and rotating anode to dissipate heat
When were the rotating anodes developed?
in 1936 to dissipate heat
What is the source of xray photons?
the anode, its 99% heat and 1% x ray production
What are the 3 ways tubes fail?
Pitting, melting, cracked anode
Actual FS vs Effective FS?
Actual comes first and is the area of electron beam on anode, effective is the path of produced photons
