Ch 7 Flashcards
Projectile electrons travel from _____.
cathode to anode
During an exposure, most of the _____ energy of the projectile electrons is converted to _____.
kinetic, heat
Most of the heat generated at the target is due to _____.
outer-shell excitation
Electron interactions at the inner-shell of the target atoms produce _____ radiation
characteristic
The useful characteristic x-rays from tungsten targets are ___-shell x-rays.
K
Characteristic K-shell x-rays have an effective energy of _____ keV.
69
Most of the x-rays produced at the target are _____.
bremsstrahlung
Bremsstrahlung x-rays are produced by _____ at the target
slowing electrons
An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of _____ keV.
100
What percentage of target interaction results in the production of x-ray photons?
1%
Xrays are produced by interactions between electrons and ___
tungsten
Incoming electrons are called
incident electrons
Target interactions occur w/in _____ of the anode surface.
0.25-0.5mm
____% of incident electrons are converted to heat
99%
As energy increases, efficiency ___
increases
Efficiency of xray tube is increased as kinetic energy _____
increases
Kinetic energy =
1/2 mv ^2
What determines kinetic energy
mass & velocity
We have control over _____ through control of KVP
velocity
During Brems, incident electron interacts with ____ of the nucleus
electric field
Electron is influenced by electric field of nucleus and _____
slows down and changes direction
In Brems, when an electron slows
an xray is produced
In Characteristic, the incident electron interacts with
Inner shell (K) and knocks it out of orbit
An electron from another shell
moves into the K shell to fill the hole
