physics
The primary components of the x-ray tube are: A.the table top and tilt control B.the anode and the cathode C.the collimator and the control console D.the tube stand and the collimator
The anode and cathode
In pair production, the positron, at the end of its range in the medium: A.comes to rest B.is annihilated resulting in two annihilation photons C.is converted to a photon D.is converted to another particle
Is annihilated resulting in two annihilation photons
Which of the following elements does not exhibit a high capture cross section for slow neutrons? A.Boron B.Cadmium C.Lead D.Lithium
Lead
Which power source is used to generate electromagnetic waves for the accelerator guide in a linear accelerator? A.Magnetron B.Betatron C.Cyclotron D.None of the above
Magnetron
During nuclear decay, energetic particles are emitted. The maximum energy of these particles is a function of the: A.Mass defect B.Neutron capture cross section C.Spin orientation of the particles D.Decay constant
Mass defect
The formula 2n2 is used to calculate: A.Minimum number of electrons in an orbital shell B.Maximum number of electrons in an orbital shell C.Total number of electrons in the atom D.Number of outer shell electrons in an atom
Maximum number of electrons in an orbital shell
All of the following apply to "absorbed dose" except: A.energy deposited at a point B.measured in Gray C.measured in air D.can measure absorbed dose using ionization chambers
Measured in air
The calibration of a linear accelerator or other radiation generator is the responsibility of the: A.Radiation therapy units B.Medical Physicist C.Radiation Therapist D.Dosimetrist
Medical physicist
Which agency provides information and recommendations in the public interest concerning radiation measurements and protection?
NCRP
Any equipment malfunctions or setup errors affecting treatment delivery must be reported to the oncologist and physicist. Malfunctions or errors resulting in misadministration must be reported to which of the following? A.Nuclear Regulatory Commission (NRC) B.Nuclear Commission of Incidence (NCI) C.Food and Drug Administration (FDA) D.Company that made the treatment unit
NRC
The frequency (hertz) of a wave can be defined as the: A.distance the wave travels B.number of cycles per second C.height of the wave D.distance between the adjacent wave peaks
Number of cycles per second
Which of the following radiation monitoring devices can measure radiation exposure as low as 1 mR? A.TLD dosimeter B.OSL dosimeter C.film badge D.all of the aboveEnone of the above
OSL dosimeter
Because of environmental factors, the manufactueres recommend ______________ as the maximum period of time that the film badge may be worn for personnel monitoring. A.Two weeks B.One month C.Three months D.Six months
One month
The sensitivity of G-M counter is directly related to its: A.Starting potential B.Operating potential C.Hydrogen D.Discharge potential
Operating potential
Excitation produced by electron beams occurs in the: A.Nucleus of the atom B.Neutrons of the atom C.Orbital electrons of the atom D.Protons of the atom
Orbital electrons of the atom
Which of the following best describes the difference between x-rays and gamma rays? A.Energy B.Velocity C.Field size D.Origin E.All of the above
Origin
The most sensitive type of personnel monitoring devices is the: A.film badge B.pocket dosimeter C.weekly blood test D.thermoluminescent dosimeter
Pocket dosimeter
The majority of the mass of the atom is derived from: A.Protons and electrons in the nucleus B.Protons and neutrons in the nucleus C.Protons, neutrons, and electrons in the nucleus D.Alpha, beta, and gamma radiation emitted
Protons and neutrons in the nucleus
The quality factor (or radiation weighting factor) is essentially a simplified version of the _______. A.f factor B.LET C.RBE D.Effective dose equivalent
RBE
Which component of a linac is not used when treating in the photon mode?
Scattering foil
The most sensitive device for the detection of gamma radiation is a special type of radiation device called a/an: A.Scintillation counter B.Ionization chamber C.Film badge D.Pocket dosimeter
Scintillation counter
According to the AAPM TG-40, the tolerance for the light/radiation field alignment is specified at plus or minus: A.1 mm B.2 mm C.3 mm D.4 mm E.5 mm
2mm
The tolerance for the localizing laser or the ODI indicator (at normal clinical distance) is:
2mm
The range of accelerator electron beams qualities commonly used in radiation therapy is: A.3 - 15 MeV B.< 3 MeV C.20 - 50 MeV D.None of the above
3-15 MeV
Which of the following is true? A.At any given photon energy, only one type of interaction is possible B.Compton, photoelectric, and pair production all decrease in probability with energy C.The most likely interaction in soft tissue for a 100 keV photon is photoelectric D.The most likely interaction in soft tissue for a 1.5 MeV photon is Compton
The most likely interaction in soft tissue for a 1.5 MeV Photon is Compton
The primary reference medium for the measurement and calculation of absorbed dose is: A.Air B.Water C.Lucite D.Polystyrene
Water
In general, radiation damage increases with increases in the: I. oxygen enhancement ratio II. quality factor of the radiation III. linear energy transfer
all the above
Protons have higher LET than gamma rays. True False
true
The workload describes: A.How much the primary beam is in use B.The fraction of the workload in which a barrier is irradiated C.The fraction of time during which an area is occupied D.Energy of the beam in use
.How much the primary beam is in use
When a radiation worker is away from work, it is best to store his personnel monitoring film badge: A.In a safe place away from the source of radiation B.In a locker inside the linear accelerator vault C.In a drawer at the linear accelertor console D.In the car for quick and easy access
.In a safe place away from the source of radiation
An elastic collision is one in which: A.The incoming electron gives all of its energy to the electron it encounters B.The incoming electron shares its energy with the electron it encounters C.The incoming electron is captured by the nucleus D.The incoming electron takes the place of an ejected electron
.The incoming electron gives all of its energy to the electron it encounters
Exposure is defined as: A.The total kinetic energy of ionis released in a unit mass of air in electronic equilibrium B.Absorbed radiation energy per unit mass of air in electronic equilibrium C.Average electron energy liberated in air D.The total charge of ions of one sign, liberated by photons, per unit mass in air
.The total charge of ions of one sign, liberated by photons, per unit mass in air
The monthly dose equivalent limit to an embryo/fetus is ________ mSv. A0.5 B.1 C.5 D.50
0.5 msv
The rest mass energy of an electron is: A.938 MeV B.1.02 MeV C.0.51 MeV D.1.02 keV E.0.51 keV
0.51 MeV
Electrons have a quality factor (QF) of:
1
What is the radiation weighting factor for gamma rays?
1
Which of the following electromagnetic radiation is most likely to interact with matter as if it were a wave? 1. Visible light 2. Microwaves 3. X-rays
1 & 2
Which of the following linac components requires(s) to be cooled: 1. Klystron or magnetron2. Targets3. Wave guides4. Focusing coils5. Transformers
1&2
Examples of primary radiation barriers include: 1. radiation therapy treatment room walls 2. lead aprons 3. radiation therapy room floors
1&3
The important QA test(s) associated with the light field are: 1. field size accuracy 2. beam output 3. light and radiation field coincidence
1&3
Exposure (X) is: 1. ionization in air 2. is the amount of charge per unit mass 3. measured using an ionization chamber
1, 2 & 3
When film badges are used for radiation monitoring, which of the following factors may affect the accurate reading of the badge? 1. Exposure to excessive heat 2. Submersion of the badge in fluids 3. Damage to the film wrapper
1, 2 & 3
When a photon traverses a medium, the following events can occur: 1. no interaction2. complete absorption3. scatter
1, 2, and 3
A film monitoring badge can be used for the measurement of ____________ sources. 1. X-ray 2. Beta 3. Gamma
1,2&3
To produce an electron-positron pair in the vicinity of a nucleus, the interacting photon must have a minimum energy of: A.0.5 MeV B.1 MeV C.1.02 MeV D.Any energy
1.02 mev
Which of the following types of radiation has the shortest wavelength? A.AM/FM radio transmission waves B.Ultraviolet radiation C.Infrared radiation D.Visible light E.120 kV X-rays
120 kV X-rays
During a split field test for longitudinal displacement of the collimator for jaw symmetry, the collimator is rotated through an angle of:
180 degree
Which of the following is not a type of ionizing radiation? A.2 MHz ultrasound B.Cobalt gamma rays C.Strontium beta D.15 MV x-rays
2 MHz ultrasound
The tolerance for localizing laser and the ODI indicator is: A.1 mm B.2 mm C.5 mm D.none of the above
2 mm
As the energy of electromagnetic radiation increases, the: 1. Frequency decreases 2. Wavelength decreases 3. Speed increases
2 only
The x-ray beam in the linac must exhibit flatness within about: A.1% B.2% C.5% D.none of the above
2%
The principle late effects of ionizing radiation on humans include: 1. local tissue damage 2. genetic effects 3. malignant disease
2&3
Select an option from (a-d) in which the following components (1-5) are arranged in the decreasing order of their distance from the patient: 1. Monitor chamber 2. Target 3. Primary collimator 4. Jaws and secondary collimator 5. Flattening filter
2,3,5,1,4
What is the radiation weighting factor for alpha particles?
20
Which of the following decays by alpha decay? A.226Ra B.60Co C.125I D.137Cs
226Ra
The constancy of linac output, when compared with the benchmark values established during commissioning, must be within: A.1% B.3% C.5% D.none of the above
3 %
The speed of all electromagnetic radiations in a vacuum is: A.3 x 1010 cm/sec B.3 x 1010 m/sec C.3 x 1010 km/sec D.Photons cannot travel in a vacuum
3x1010 cm/sec
The energy range for the early generation superficial therapy machines is: A.50 to 150 kV B.150 to 500 kV C.600 to 1000 kV D.20 to 25 MeV
50 to 150 kV
The annual equivalent dose limit to skin, hands, and feet (in mSv) is:
500 mSv
The range of accelerator photon beam qualities commonly used in radiation therapy is: A.6 - 21 MV B.2 - 6 MV C.25-50 MV D.none of the above
6-21 MV
If space is not restricted, concrete is used in preference to lead for primary shielding in a 15 MV linac installation because: A.Concrete is less expensive B.Concrete is more efficient than lead for neutron shielding C.Lead would weight too much D.A, B, C E.A, B only
A & B
Photoelectric effect involves: A.a bound electron B.an unbound electron C.an nuclear interaction
A bound electron
A Compton interaction involves a photon interacting with: A.a free electron B.a tightly bound electron C.more than one electron D.all the electrons of the atom
A free electron
To check the accuracy of grantry digital readouts one could use: A.Closed collimators B.A spirit level at 45 degree angle increments C.A breast bridge at 90 degree angle increments D.A spirit level at 180 degree angle increments
A spirit level at 45 degree angle increments
The process for testing a new accelerator against manufacturer's specifications before putting it into service is termed: A.Insurance calibration testing B.Acceptance testing C.Error correction testing D.Quality assurance testing
Acceptance testing
A mechanical distance indicator is used to verify: A.Gantry rotation B.Collimator rotation C.Field size congruence D.Accuracy of optical distance indicator
Accuracy of optical distance indicator
Components of a modern x-ray tube include: A.cathode filament B.rotating anode C.glass envelope D.all of the above
All of the above
Thermoluminescent dosimeters: A.Are most commonly composed of lithium fluoride (LiF) B.Are re-usable C.Output an amount of light proportional to the radiation energy absorbed when heated to 300 - 400º C D.All of the above
All of the above
From internal hazard point of view, the most hazardous radiation is: A.alpha rays B.beta rays C.gamma rays D.neutrons
Alpha rays
Which type of nuclear radiation has the shortest range in tissue (Assume equal energy)? A.Gamma rays B.Betas C.Neutrinos D.Alphas E.Neutrons
Alphas
The target to patient distance is measured using: A.a meter scale B.an SSD rod C.an ODI indicator D.none of the above
An ODI indicator
A positron is an antiparticle of: A.A proton B.A neutron C.An electron D.A photon E.A muon
An electron
Concerning pair production, which of the following is true? A.The threshold energy for pair production is 0.51 MeV B.An electron and a positron are produced C.The total energy of the incident photon is divided between the kinetic energies of the pair particles D.Annihilation produces 1.02 MeV photonsEA pair of electrons is produced
An electron and a positron are produced
Beam calibration at the hospital must be carried out using A.a Fricke dosimeter B.film C.a semiconductor dosimeter D.an ionization chamber
An ionization chamber
The wavelengths of x-rays are measured in: A.millimeters B.centimeters C.Roentgens D.Angstroms
Angstroms
In positron emission tomography (PET), the image is created by detecting: A.Positrons B.Auger electron C.Characteristic x-rays D.Annihilation photons E.None of the above
Annihilation photons
Full calibration and overhaul of treatment equipment must be carried out: A.Daily B.Weekly C.Monthly D.Annually
Annually
The positive side of the basic x-ray tube is known as the:
Anode
The inverse square law is valid for A.Visible light B.Diagnostic X-rays C.Therapeutic X-rays D.Gamma rays E. Any electromagnetic radiation emanating from a point source
Any electromagnetic radiation emanating from a point source
The number of protons and neutrons in the nucleus is known as: A.atomic weight B.strong force C.atomic mass number D.nuclear stability
Atomic mass number
The reduction in the number and energy of photons as radiation passes through matter is termed: A.irradiation B.deflection C.photoelectrolysis D.attenuation
Attenuation
When determining shielding for a treatment room, which type of radiation need not be accounted for? A.Neutrons B.Primary C.Secondary D.Background
Background
The System International unit for activity is the: A.Becquerel B.Curie C.Hertz D.Roentgen
Becquerel
In a linear accelerator with a horizontally mounted waveguide, the component that directs the electron beam to the output window from the accelerator guide is: A.a klystron B.an electron gun C.a high-voltage power supply D.a bending magnet E.a thyratron
Bending magnet
Lipowitz metal is composed of:
Bismuth, lead, tin, cadmium
The basic method of determining the absorbed dose in a medium due to its production of heat is termed: A.Chemical dosimetry B.Fricke dosimetery C.Calorimetry D.Thermometry
Calorimetry
Which of the following is considered a late effect following a large single exposure to radiation? A.Chromosomal aberrations B.Carcinogenesis C.Temporary sterility D.Desquamation
Carcinogenesis
In the megavoltage energy range the predominant interaction in patient is: A.Pair production B.Compton C.Photoelectric effect D.Thompson scattering
Compton
If a technologist were to stand 2 m away from a patient during fluoroscopy (outside the primary beam) the dose received by the technologist would be mainly due to: A.Compton electrons B.Photoelectrons C.Compton scattered photons D.Characteristic x-rays generated in the patientECoherent scatter
Compton scattered photons
An incoming photon of 1 MeV interacts with an orbital electron causing ionization of the atom and a 9 MeV scattered photon. This describes an event called: A.pair production B.photoelectric interaction C.Compton scattering
Compton scattering
Elastic scattering is characterized by: A.Conservation of kinetic energy B.Non-conservation of kinetic energy C.Nonconservation of angular momentum D.Nonconservation of momentum
Conservation of kinetic energy
The SI unit of radiation exposure is the: A.Roentgen B.Coulomb/kilogram C.Sievert. DGray EJoule/kilogram
Coulomb/kilogram
Which of the following machines does not accelerate electrons? A.Microtron B.Betatron C.Cyclotron D.X-ray tube
Cyclotron
The constancy of linac output for photon and electron beams (of at least one energy) must be checked: A.daily B.weekly C.monthly D.only during commissioning
Daily
Compton scatter: A.Takes place primarily with inner shell bound electrons B.Is an interaction with the nucleus C.Is more likely at energies just below the K edge D.Decreases in probability as photon energy increases E.Is responsible for the eficiency of lead as a diagnostic room shielding material
Decreases in probability as photon energy increases
The number of electrons in the outer shell of an atom: A.Is always 2n2 B.Is greater for radioactive isotopes than for stable isotopes of the same element C.Determines the chemical properties of the atom D.Is always between 8 and 16 E.Is 1 for all inert gases
Determines the chemical properties of the atom
The most significant source of "manmade" radiation dose to the U.S. population as a whole is from: A.High-altitude air travel B.Television receivers and other consumer products C.Fallout from nuclear weapons exploded in the atmosphere D.Diagnostic radiological examinations E.Nuclear reactor effluents
Diagnostic radiological examinations
An x-ray photon passes into a cell and strikes a chromosome, causing a point mutation in a DNA molecule. This is classified as a/an: A.Direct effect B.Indirect effect C.Pinhole effect D.Threshold effect
Direct effect
A resident checking on an in-patient with a 137Cs insertion wishes to reduce his/her exposure. Which of the following would be the most effective? A.Reducing time spent with the patient by half B.Wearing a lead apron C.Using a lead shield of thickness one HVL D.Doubling the distance from the patient E.All of the above have about an equal effect
Doubling the distance from the patient
The relationship between photon frequency ν and energy E can be expressed using Plank's constant h as: A.h = Eν B.E = hν CE = h/ν D.E = ν/h E.None of the above
E=hv
The source of electrons in an electron accelerator is the:
Electron Gun
Characteristic radiation emission occurs when: A.Electrons move from lower to higher orbital shells B.Electrons move from higher to lower orbital shells C.The atom has an unstable nucleus D.The atom undergoes nuclear fission
Electrons move from higher to lower orbital shells
In a thermoluminescent dosimeter, the amount of light obtained when the crystal is heated is proportional to the _____________ by the crystal. A.Energy absorbed B.Radiation emitted C.Both of the above D.Neither of above
Energy absorbed
To interact by photoelectric effect, the interacting photon must have energy: A.Less than the binding energy of the orbiting electron B.Equal to or greater than the binding energy of the orbiting electron C.Of any level D.Of at least 1 MeV
Equal to or greater than the binding energy of the orbiting electron
To interact by photoelectric effect, the interacting photon must have an energy: A.less than the binding energy of the electron in question B.equal to or just greater than the binding energy of the electron C.any energy D.a minimum energy of 1 MeV
Equal to or just greater than the binding energy of the electron
All of the following are advantages of the film badge personnel monitor except: A.Provides permanent record B.Exposure to interpretation delay C.Measure dose over large body area D.Radiaiton type can be determined
Exposure to interpretation delay
The agency that regulates the use of radiation producing machines is the: A.APM B.NRC C.DOT D.FDA
FDA
Radiographers must wear the OSL badge at the waist. T or F
False
There are three major quantities that are important in radiation physics. They are radiation exposure, radiation absorbed dose, and radiation dose equivalent. T or F
False
All of the following are radiation protecting devices except: A.lead apron B.lead glasses C.thyroid shield D.film badge
Film badge
Which of the following radiation devices do heat and humidity affect?
Film badge
In treatments using kilovoltage equipment, filters are used to: A.filter low-energy x-rays B.shield the patient from all radiation exposure C.collimate the beam D.increase quantity
Filter low energy x-rays
The highest electron binding energy of an atom is found in the electron's ___________ level. A.First energy orbital B.Second energy orbital C.Third energy orbital D.All are the same
First energy orbital
The energy of an electromagnetic radiation is directly proportional to its: A.Frequency B.Wavelength C.Velocity D.a and b
Frequency
Which of the following is the electromagnetic radiation with the highest frequency? A.Infrared B.Gamma C.Radio waves D.Ultrasound E.Ultraviolet
Gamma
The photoelectric effect occurs when an atom is ionizied by: A.alpha rays B.beta rays C.gamma rays D.none of the above E.any of the above
Gamma rays
Which of the following is classified as a rate meter? A.Geiger-Muller counter B.Thermoluminescent dosimeter C.Pocket dosimeter D.Film badge
Geiger muller counter
Radioactivity was discovered by:
Henri Becquerel
High LET radiation usually has: A.An RBE of 1 B.An RBE of 0 C.High RBE D.No relation to RBE
High RBE
The linear energy transfer of an x-ray or gamma photon is low because of its: A.Low energy B.High penetration C.Negative charge D.Positive charge
High penetration
Which type of radiation detection devices are most desirable for cumulative radiation monitoring? I. GM counters II. TLD's III. Film badges
II & III
Which of the following materials are used in room shielding? I. Cerrobend II. concrete III. lead IV. steel
II, III & IV
Whan an electron is removed from an atom, the atom is said to be: A.radioactive B.ionized C.inert D.metastable
Ionized
In pair production, after expending energy for the creation of the pair, the excess photon energy: A.appears as a scattered photon B.is shared by the electron and positron C.goes only to the electron D.goes only to the positron
Is shared by the electron and positron
One disadvantage of radium is: A.It has a long half-life B.It decays by alpha emission C.It is not as effective as other radioisotopes D.It decays to form a radon, a dangerous gas
It decays to form a radon, a dangerous gas
The kinetic energy of charged ionizing particles liberated per unit mass in a specific material by uncharged particles is known as the: A.KE factor B.KP factor C.Kerma D.Gray
Kerma
The gantry head of the linear accelerator contains all of the following except: A.Flattening filter B.Ion chamber C.X-ray target D.Klystron
Klystron
Thermoluminescent dosimeters are composed of _____. A.Ra B.Al2O3 C.Ce D.LiF
LiF
An electron with the lowest binding energy is most likely located in the: A.K shell B.L shell C.M shell D.All binding energies are the same
M shell
The schematic display most often employed to represent the structure of the atom was developed by: A.Charles Dalton B.Neils Bohr C.Michael Crookes D.Charles Darwin
Neils Bohr
In a Compton interaction, the photon loses: A.all its energy B.part of its energy C.no energy
Parts of its energy
At energies above 10 MeV, x-ray photons may interact directly with the atomic nucleus causing the emission of nuclear fragments in a process termed: A.Photodisintegration B.Annihilation reaction C.Triplet production D.Magnetic resonance
Photodisintegration
An individual packet of energy that interacts with matter in a specified manner according to the laws of electromagnetic forces is called a: A.Vector B.Disturbance C.Photon D.Spiral
Photon
Which of the following radionuclides is most likely to decay by alpha decay? A.C14 B.Mo99 C.Sn113 D.Po218
Po 218
A neutral atom that loses an electron by ionization is called a: A.negative atom B.positive atom C.negative ion D.positive ion
Positive ion
Different isotopes of the same element will have equal numbers of ___________. A.Electrons B.Protons and electrons C.Neutrons D.Electrons and neutronsEProtons and neutrons
Protons and electrons
Which of the following devices is NOT normally employed for the determination of the occupational dose equivalent limit of a radiation therapist? A.Film badge monitor B.Pulse and blood oximeter C.Thermoluminescent dosimeter D.Pocket dosimeter
Pulse and blood oximeter
The roentgen is a unit of: A.Radioactivity B.Radiation exposure C.Absorbed dose D.Equivalent dose E.Ionization
Radiation exposure
The binding energy of an electron in an atom is the minimum energy: A.Required to remove the electron from the atom B.Required to move the electron from an inner shell to the next shell C.Of an incident photon that enables pair production D.Of an incident photon that could cause the atomic nucleus to change its composition
Required to remove the electron front the atom
Which of the following processes invloving electromagnetic radiation is mostly responsible for the dose to personnel in the operating room during intraoperative radiation? A.Activation B.Excitation C.Reflection D.Scatter E.Refraction
Scatter
Which of the following is not a basic component of a film monitoring badge? A.Plastic holder B.Various metal filters C.Light-tight pocket D.Self-reading meter
Self reading meter
Most of the neutrons contaminating a linac photon beam are produced in the ____________. A.Patient B.Target, flattening filter, and collimators C.Shielding material in the walls D.Air between the x-ray source and the patient
Target, flattening filter, and collimators
Regarding linac output, AAPM's TG40 report on Quality Assurance recommends all of the following except: A.The daily output constancy check should be within 10% of the standard B.The output is checked monthly by the physicist, and should be within 2% of the correct value C.Action should be taken if parameters exceed tolerance D.At the annual calibration the ouput must be within 2% of the required value
The daily output constancy check should be within 10% of the standard
When calculating room shielding, the use factor, U, refers to: A.The weekly dose at the isocenter B.The fraction of operating time that the area in question is occupied C.The fraction of operating time that the beam is directed towards the barrier D.The fraction of the work week that the machine is in operation E.None of the above
The fraction of operating time that the beam is directed towards the barrier
Ionization implies: A.An excited state of the atom B.The production of x-rays C.The removal of an electron from the atom D.A neutral state of the atom
The removal of an electron from the atom
Pocket ionization chambers are not normally employed in a radiology personnel monitoring program because: A.They require daily attention and recording B.They are not sufficiently accurate C.They are difficult to read D.They have a long reading delay time
They require daily attention and recording
A monitoring device which is worn on the outside of a lead apron at the level of the collar is primarily intended to measure the dose to the: A.Auditory ossicles B.Pituitary gland C.Humeral epiphysis D.Thyroid gland
Thyroid gland
A bending magnet in an accelerator may be used: A.to help deflect microwave power B.to deflect (bend) the electron beam C.gather stray electrons together in a bunch D.gather random paper clips
To deflect (bend) the electron beam
A scattering foil is used in the clinical accelerator: A.to reduce the electron energies B.to produce bremsstrahlung C.to spread the accelerator "pencil beam" into a larger field for treating patients. D.for none of the above
To spread the accelerator "pencil beam" into a larger field for treating patients
What type of target is used in high-energy linear accelerator? A.Transmission type B.Reflection type C.Refraction type D.None of the above
Transmission type
Inherent filtration is due to materials present in the x-ray tube itself that the beam must pass through. T or F
True
The sensing material in a TLD dosimeter is lithium flouride. T or F
True
If a 6-MeV photon undergoes pair production, which of the following is true? A.Two 0.51 MeV photons will be emitted B.A 4.98-MeV photon is scattered C.6 MeV is shared as kinetic energy between a positron and an electron D.Two positrons are emitted at 180° to each other
Two 0.51 MeV photons will be emitted
As the wavelength of light is decreased, its speed is: A.Increased linearly B.Decreased linearly C.Unchanged D.Increased exponentially
Unchanged
To undergo a Compton effect, the energy of the interacting photon must be: A.less than the binding energy of the electron in question B.equal to the electron binding energy C.very much larger than the electron binding energy D.any energy
Very much larger than the electron binding energy
The production of free radicals in a living tissue most often occurs from the irradiation of: A.water B.RNA C.proteins D.salt
Water
The energy of an electromagnetic radation is inversely proportional to its: A.Frequency B.Mass C.Speed D.Wavelength
Wavelength
In an accelerator the source of microwave energy is a klystron or a magnetron. Yes or No
Yes
X-rays are produced by decelerating high speed electrons in a target. Yes or No
Yes
A photon detected following a photoelectric effect interaction is most likely to be ____________. A.The scattered incident photon B.A gamma ray C.An annihilation photon D.A characteristic x-ray E.Cerenkov radiation
a characteristic x-ray
Megavoltage photons can be detected by all of the following except: A.An ion chamber B.A Geiger counter C.A diode D.A Thermoluminescent Dosimeter (TLD) E.A flow meter
a flow meter
The target of the linac must have: a. a low melting point b. a high melting point c. the ability to bend d. low thermal conductivity
a high melting point
What quantity is measured directly by the TLD? A.Exposure B.Absorbed dose C.Activity D.Lag time
absorbed Dose
Which of the following sections of the linear accelerator must be gas-evacuated to insure its proper operation? A.Electron gun B.Magnetron C.Accelerator tube D.Treatment head
accelerator tube
During x-ray production, the resulting x-ray beam comes from electrons colliding with the target causing interactions such as: A.Characteristic radiation B.Bremstrahlung radiation C.Auger electron D.All of the above
all the above
In a photoelectric interaction, the photon loses: A.all the energy B.part of the energy C.no energy
all the energy
226Ra decays to 222Rn by ________ decay. A.Beta minus B.Alpha C.Gamma D.Beta plus
alpha
The ALARA concept holds that occupation exposure of the radiographer should:
be kept as low as reasonably achievable
The relationship between photon speed c, wavelength λ, and frequency ν is: A.c = λ * ν B.ν = c * λ C.λ = c * ν D.λ = ν/c E.None of the above
c = λ * ν
The photons produced during the orbital transitions of electrons from a higher to lower energy are called: A.Characteristic radiation B.Corpuscular radiation C.Gamma radiation D.Vacancy radiation
characteristic radiation
An incident x-ray photon of 37 keV strikes an electron with a 40 keV binding energy. A scattered photon results with 37 keV of energy this describes a: A.Compton event B.Bremsstrahlung event C.Photoelectric event D.Coherent scatter
coherent scatter
In the construction of a new radiation therapy center, the choices for primary barriers include concrete, lead, or iron. Measure for measure, I would need more __________ for adequate absorption.
concrete
The probability of Compton interaction: A.increases with increasing photon energy B.decreases with an increase in photon energy C.is independent of photon energy D.increases and then decreases with photon energy
decreases with an increase in photon energy
A collimator: A.flattens the beam at a specified depth in tissue B.defines the beam C.determines the dose rate D.stops the scatter radiation
defines the beam
Which is not true of the electromagnetic spectrum? They all have the same: A.Velocity B.Energy C.Mass D.Charge
energy
Sievert is a unit of: A.Exposure B.Equivalent dose C.Absorbed dose D.Dose rate E.Energy
equivalent dose
The exposure or exposure rate in air is converted to dose or dose rate in a medium using the: A.stopping-power ratio B.W-quantity C.f-factor D.exposure calibration factor E.G-value
f-factor
Maximum exposure rate at a specific distance from a patient following insertion of radioactive sources can be measured with TLDs. T or F
false
The number of waves passing through a point in a specified unit of time is termed: A.Frequency B.Wavelength C.Persistence D.Modulation
frequency
The radiation detection device helpful in finding a lost radioactive source would be a/n: A.Ion chamber B.Geiger-Muller counter C.TLD D.Neutron counter
geiger-muller counter
The SI unit of absorbed dose from ionizing radiation is the:
gray
The amount of energy absorbed in a medium is expressed in units of: A.Roentgen B.Coulomb/kilogram C.Sievert D.Gray
gray
Low-energy photon beams are calibrated with an ion chamber: A.in air B.in a plastic phantom at dmax cm depth C.in a water phantom at dmax depth D.in a water phantom at 10 cm depth E.in a water equivalent phantom at 10 cm depth
in air
Radiation can be described as energy: A.In transit B.Destroyed C.Recovered D.In the form of heat
in transit
The use of additional filtration in a therapeutic x-ray machine is primarily intended to: A.increase beam quality B.reduce anode heel effect C.increase skin exposure. D.reduce auger electron emissions
increase beam quality
If the distance from a radiation source is decreased by half, the intensity is: A.Increased by half B.Increased by four times C.Decreased by half D.Decreased by a quarter
increased by four times
The majority of damage to the body from exposure to x-rays and gamma rays results from the: A.direct effect B.indirect effect C.target effect D.threshold effect
indirect effect
Which of the following detectors require corrections in measuring percentage depth dose in electron beams? A.Ion chamber B.Film C.Unshielded diode D.TLD chips E.All of the above
ion chamber
Monitoring of dose rate, making integrated dose measurements and surveys of field symmetry, are best accomplished using a/an:
ion chamber detector
Which detector is used in accelerators as a monitor chamber? A.Proportional counter B.Ionization chamber C.Diodes D.Photographic film
ionization chamber
In Compton scattering the enrgy of the incident photon: A.should be slightly greater than the electron binding energy B.is equal to the energy of the scattered photon and the recoil electron C.increases with scattering angle D.gets divided between a pair of charged particles
is equal to the energy of the scattered photon and the recoil electron
Elements that have the same Z but different A are called: A.Isotopes B.Isomers C.Isotones D.Isobars E.None of the above
isotopes
Which of the following is the accelerator component that supplies pulses of high-power radiofrequency microwave energy to accelerate injected electrons? A.klystron B.electron gun C.high-voltage power supply D.bending magnet E.thyratron
klystron
In coherent or Rayleigh scatter of a photon from an atom, the energy of the incident photon is: A.Fully absorbed by the atom B.Reduced by the amount depending on the scatter angle C.Reduced by 1.02 MeV regardless of the scatter angle D.Left unchanged E.None of the above
left unchanged
The principal hazard from indoor radon involves: A.Whole body dose from gamma rays B.Skin dose from betas C.Lung dose from alpha emission D.Bone dose from deposited radionuclides
lung dose from alpha emission
A neutral atom that gains an electron will have a: ANeutral charge BNegative charge CPositive charge
negative charge
In an accelerator, the electrons are accelerated by an alternatign a.c. voltage. yes or no
no
MLCs used with various linacs are identical. A Yes B No
no
For a phantom to be nearly tissue equiavlent for measuring depth dose distribution in megavoltage photon beams, which one of the following properties should it have approximately the same as soft tissue? A.Number of electrons per unit mass B.Number of electrons per unit volume C.Mass per unit volume D.Effective atomic number
number of electrons per unit volume
_______________ takes into consideration how an area on the other side of an irradiated wall is going to be used. A.Workload B.Occupancy factor C.Use factor D.Barrier factor
occupancy factor
A controlled area is one that is: A.restricted to access by non-radiation workers only B.monitored by survey meters C.occupied by radiation workers D.occupied by the general population
occupied by radiation workers
Which of the following is an example of a low-energy photon beam? A. 6 MV x-ray B. 1.25 MeV gamma ray C. Orthovoltage beam D. 3 MeV electrons E.6 MeV neutrons
orthovoltage beam
A flattening filter A.preferentially reduces the photon intensity in the cental region of the beam B.hardens the beam at off axis points compared tot he central axis point C.broadens the photon beam to obtain larger field sizes D.positioning is not important as long as it is in the beam path
preferentially reduces the photon intensity in the cental region of the beam
The cyclotron may produce _________ beams. A.Electron B.X-ray C.Proton D.Gamma ray
proton
The wave-particle duality of radiation is described by (the): A.Coulomb's law B.Einstein's theory C.Ohm's law D.Quantum theory
quantum theory
Which of the following is not an SI unit? Answer Choices A.Meter B.Kilogram C.Second D.Rad E.Becquerel
rad
The roentgen is a unit of: A.radioactivity B.radiation exposure C.absorbed dose D.equivalent dose E.ionization
radiation exposure
The largest dose from natural background radiation comes from: A.Terrestrial B.Radon C.Cosmic D.Internal
radon
The unit for dose equivalent, H, is expressed in: A.Sievert B.Gray C.rad D.roentgen
sievert
Which of the following was used first to measure radiation exposure and set limits: A.Skin erythema dose B.Tolerance dose C.MPD D.Dose limits
skin erythema dose
In the producation of bremsstrahlung, the electron: A Ejects a cloud of electrons B Slows down and loses some of its energy as an x-ray photon C Produces a heavy particle D Ejects an electron from the atom
slow down and loses some of its energy as an x-ray photon
Which of the following is needed for checking collimator rotation accuracy? A.Spirit level B.Metric ruler C.Film D.Shielding blocks
spirit level
Which has the highest photon energy? A.Radiowaves B.Ultraviolet light C.Microwaves D.Infrared
ultraviolet light
The term quality factor (Q): A.Varies with different types of radiation B.Varies with different types of tissue C.Varies as a function of age and gender D.Is measured in rem
varies with different types of radiation
