Black and Yellow Flashcards
(220 cards)
Regarding linear accelerators, which of the following is TRUE?
a. Maximum photon energy is equal to the E of the electron striking the target
b. The bending magnet is rotated out of the beam in the electron mode
c. The beam current is higher in the electron mode than in the photon mode
d. The scattering foil is the primary component for photon production.
a. Maximum photon energy is equal to the E of the electron striking the target
1 mSv is equal to ____ rem
0.1 rem
If the total body is exposed to a dose of 4500 cGy in a single exposure, the most likely cause of death would be:
a. infection and low blood counts
b. Severe damage to the intestines
c. Cerebral edema
d. Death would not be likely with dose
c. Cerebral edema
By what factor does the intensity decrease when someone moves 10 meters to 20 meters away from a radioactive source?
a. 2
b. 4
c. 10
d. 20
b. 4
What is the allowable cumulative exposure for a radiation worker?
a. one rem X the workers age in yrs
b. five rem X the workers age in decades
c. 100 rem X the workers age in yrs
a. one rem X the workers age in yrs
Which of the following are interacions between an incident photon and an atomic nucleus?
a. Photoelectric
b. Compton
c. Coherent
d. Pair Production
d. Pair Production
A barrier that attenuates the useful portion of the beam to be required degree is known as?
a. Secondary Barrier
b. Incident Shielding
c. Tenth Value Layer
d. Primary Barrier
d. Primary Barrier
A “star” shot on a linear accelerator is performed to test the rotational axis of the :
- collimator
- couch
- gantry
a. 1 and 2 only
b. 2 and 3 only
c. 1 and 3 only
d. 1, 2, and 3
d. 1, 2, and 3
Direct exposure to lasers that are used for patient alignment purposes can be a hazard for the
a. Pituitary
b. Retina
c. Commissure
d. Inner Ear
b. Retina
The average photon beam energy produced by a 6 MV linear accelerator is approx _____ MV:
a. 2
b. 4
c. 6
d. 9
a. 2
Which of the following tisues arise from mesenchymal stem cells (MSC)?
- Blood
- Cartilage
- Bone
a. 1 only
b. 2 only
c. 2 and 3 only
d. 1, 2, and 3
d. 1, 2, and 3
In bremsstrahlung radiation, the incoming electron:
a. ineracts with an orbiting electron
b. is deflected by the nucleus of the atom
c. creates a positive and negative ion
d. cascades to a lower energy state
b. is deflected by the nucleus of the atom
Exposure is:
a. Measure of ionization in air
b. Known is a biological dose equivalent
c. The absorbed dose multiplied by the quality factor
d. The possibility of a random interacion
a. Measure of ionization in air
Which of the following does not ionize directly?
a. Proton
b. Neutron
c. Alpha particle
d. Electron
b. Neutron
The half life of cobalt-60 is:
5.3 yrs
Linear accelerators have which of the following type of target?
a. Hooded anode
b. Waveguide
c. Transmission
d. Rotating cathode
c. Transmission
Klystrons and Mangetrons are:
a. Radiaion monitors
b. Microwave sources
c. Monitors used for mechanical motions
d. Beam shaping devices
b. Microwave sources
Which of the following is the most common metastatic site for prostate cancer?
a. Lung
b. Liver
c. Bone
d. Brain
c. Bone
The last part of the colon that leads into the rectum is known as the:
a. Ascending colon
b. Hepatic colon
c. Descending colon
d. Sigmoid colon
d. Sigmoid colon
Why do high E photon accelerators require flattening filters?
a. To increase the penetrating ability of the beam
b. To reduce dose rates to a safe level
c. To filter out low E photons
d. To decrease the intensity along the central axis
d. To decrease the intensity along the central axis
Lead alone could be used in room shielding when the following interactions predominate:
a. Photoelectric
b. Bragg Peak
c. Pair production
d. Compton scattering
a. Photoelectric
The intensity of a radiation beam is measured at a distance of 100 cm and is found to be 150 cGy/min. What is the intensity of this beam at 105 cm?
a. 136 cGy/min
b. 143 cGy/min
c. 157 cGy/min
d. 165 cGy/min
a. 136 cGy/min
Inv sq law
(old distace / new distance) ² x dose
(105 cm/100cm)² x 150 cGy/min
136.05 cGy/min
What does ALARA mean?
As Low As Reasonable Achievable
The most common thermoluminescence material used in radiation dosimetry is:
a. CaSO4
b. LiF
c. CaF2
d. Li2B
b. LiF
Lithium Flouride