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Rad Prot Unit 1
Bushong 8.1-3
Question | Answer |
---|---|
The kinetic energy of the projectile electron in an x-ray tube is how efficient in the production of x-rays? | 1% efficient in the production of x-rays |
Useful characteristic x-rays are produced in tungsten: | By the removal of K-shell electron |
An L-shell electron (26keV) is removed from an atom with the M-shell of 4keV and N-shell of 1keV. If a free electron fill the vacancy in the L-shell, the characteristic x-ray produced will have the energy of: | 26 keV |
The energy of characteristic x-rays increases with increasing: | Atomic number of target material |
X-rays are produced when: | Projectile electrons interact with target atoms |
Characteristic x-rays: | Are characteristic of target Z |
When a tungsten-targeted x-ray tube is operated at 68kVp: | K-shell characteristic x-rays cannot be produced AND some projectile electrons may have 68keV of energy |
According to the table on page 111: | tungsten has a greater number of electrons than molybdenum (more energy levels=more electrons) |
When characteristic x-rays are produced, the energy is characteristic of: (2) | The atomic number of the target AND the electron binding energy |
Gold is the target material: K=81, L=14, M=3, N=1. What is the characteristic x-rays that would be produced at 90kVp? | 67 keV (81-14=67) |
The KINETIC energy of a projectile electron can be measured in? | Joules |
The efficiency of x-ray production is independent of? | Tube current |
In a tungsten-targeted x-ray tube operated at 90kVp, the MOST abundant x-ray would be a? | 30 keV Brems x-ray |
Which of the following electron transitions result in the MOST useful bremsstrahlung x-ray? 1. L to K ; 2. M to K ; 3. M to L; 4. O to K ; 5. None of the above | 5. None of the above |
Bremsstrahlung radiation is produced by: | Conversion of projectile electron's kinetic energy to electromagnetic energy |
When a Bremsstrahlung x-ray is produced the projectile electron loses? | Energy |
In Bremsstrahlung x-ray production, the projectile electron is from the ___________. | Cathode |
If an average radiographic technique is used most x-rays are? | Bremsstrahlung |
Bremsstrahlung x-rays are produced only at energies up to? | Energies up to the projectile electron energy |
If radiographic technique is 74kVp/80mAs: | Bremsstrahlung x-ray energy increases if the voltage is increased to 84kVp |
If radiographic technique in a tungsten target at 60kVp/80mAs is changed to 80kVp/80mAs: | The number of x-rays produced increases |
Brems x-rays produced in a tungsten targeted x-ray tube outnumber?: | Outnumber characteristic x-rays |
When a bremsstrahlung x-ray is emitted...it is the result of? | Results from the conversion of kinetic energy |
The wavelength of an x-ray becomes longer as? | Becomes longer as the projectile electron kinetic energy is reduced |
When a projectile electron energy is increased, more _________ are produced | More Bremsstrahlung x-rays are produced |
The efficiency of bremsstrahlung x-ray production increases with increasing _______ | Target atomic number |
The output intensity of an x-ray tube is (primarly due to ____________)? | Primarily due to bremsstrahlung x-rays |
Removal of what, in projectile-target interactions will result in emission of x-rays? | Removal of inner-shell electrons |
When a projectile electron enters a target atom and interacts with the nuclear force field (what happens to the velocity): | It decreases in velocity |
The area under the curve of the x-ray emissions spectrum represents: | The total number of x-rays |
Normally the x-ray emissions spectrums contains: | Both characteristic and bremsstrahlung x-rays |
The characteristic x-ray emission spectrum principally depends on what? | Target material |
what factor explains the low number of x-rays produced at low energy? | Added filtration |
The x-ray emission spectrum represents: | X-rays emitted from the x-ray tube |
A diagnostic x-ray beam contains: | Mostly bremsstrahlung x-rays, and some characteristic x-rays |
What factor principally accounts for the reduced x-ray intensity at low energy? | Added filtration |