What process describes an atom or molecule gaining or losing electrons to acquire a charge?
A. Ionization
B. Conduction
C. Polarization
D. Radioactivity
A
In a gas detector, what attracts the positively charged particles?
A. Anode
B. Capacitor
C. Cathode
D. Power source
C
What component of a gas-filled detector measures voltage or current?
A. Anode
B. Cathode
C. Capacitor
D. Meter
D
What type of gas detector operates in the ionization region at approximately 150V?
A. Ionization survey meter
B. GM survey meter
C. Dose calibrator
D. Proportional counter
C
What is the purpose of the isotope selector buttons on a dose calibrator?
A. To adjust the applied voltage
B. To select the appropriate current-to-activity conversion factor
C. To change the geometry of the chamber
D. To measure different types of radiation
B
Which of the following is NOT a quality control test for a dose calibrator?
A. Constancy
B. Geometry
C. Accuracy
D. Sensitivity
D
What type of radiation is a GM survey meter particularly sensitive to?
A. Alpha radiation
B. Beta radiation
C. Gamma radiation
D. Neutron radiation
C
What is the definition of dead time in a radiation detector?
A. The time it takes for the detector to recover after a power outage
B. The minimum time separation required for two radiation events to be recorded as separate events
C. The time it takes for the detector to warm up before use
D. The time it takes for the detector to process a single radiation event
B
Which type of survey meter is better suited for contamination surveys?
A. Ionization survey meter
B. GM survey meter
C. Both are equally suited
D. Neither is suitable for contamination surveys
B
What is the recommended frequency for annual accuracy checks and calibration of ionization survey meters and Geiger counters?
A. Daily
B. Weekly
C. Monthly
D. Annually
D
Why are gas-filled detectors generally inefficient for high-energy photons?
A. High-energy photons are more likely to pass through the gas without interacting.
B. High-energy photons cause excessive ionization, saturating the detector.
C. High-energy photons damage the detector components.
D. High-energy photons require a different type of gas for detection.
A
What is the term for the process of creating a spark in a scintillation detector?
A. Ionization
B. Scintillation
C. Amplification
D. Discrimination
B
What material in a photomultiplier tube (PMT) absorbs scintillation photons?
A. Anode
B. Dynodes
C. Focusing grid
D. Photocathode
D
What is the purpose of the dynodes in a PMT?
A. To absorb scintillation photons
B. To convert light photons into electrons
C. To amplify the electron signal
D. To collect electrons at the end of the tube
C
What is the typical voltage applied to the dynodes in a PMT?
A. 10 volts
B. 100 volts
C. 1,000 volts
D. 10,000 volts
C
Which electronic component in a scintillation detector is attached directly to the PM tube to minimize signal distortion?
A. Amplifier
B. Preamplifier
C. Pulse height analyzer
D. Scalar/timer
B
What does a pulse height analyzer (PHA) do?
A. Amplifies the signal from the PM tube
B. Counts the number of pulses received
C. Evaluates the size of the pulse and correlates it with gamma ray energy
D. Converts the analog signal to a digital signal
C
What type of analyzer can count more than one photon energy at the same time?
A. Single channel analyzer
B. Multi-channel analyzer
C. Both single and multi-channel analyzers
D. Neither single nor multi-channel analyzers
B
What does the x-axis of an energy spectrum represent?
A. Number of counts
B. Time
C. Pulse height
D. Energy resolution
C
What is the term for the broadening of the photopeak in an energy spectrum?
A. Compton scatter
B. Peak broadening
C. Energy resolution
D. Backscatter peak
B
Which type of photon interaction with matter involves the complete absorption of the photon's energy by an atom?
A. Photoelectric effect
B. Compton scattering
C. Pair production
D. Bremsstrahlung radiation
A
What is the term for the electron ejected from an atom during the photoelectric effect?
A. Auger electron
B. Photoelectron
C. Recoil electron
D. Positron
B
What is the minimum photon energy required for pair production to occur?
A. 0.511 MeV
B. 1.022 MeV
C. 2.044 MeV
D. There is no minimum energy requirement for pair production
B
What happens to the positron produced during pair production?
A. It is absorbed by the nucleus
B. It decays into a proton and an electron
C. It undergoes annihilation with an electron, producing two 511 keV photons
D. It escapes the atom and travels through matter
C
What type of radiation is produced when a charged particle undergoes rapid deceleration?
A. Alpha radiation
B. Beta radiation
C. Bremsstrahlung radiation
D. Characteristic x-rays
C
What is an Auger electron?
A. An electron ejected from an atom during the photoelectric effect
B. An electron ejected from an atom during Compton scattering
C. An electron ejected from an atom due to the energy released when an outer-shell electron fills an inner-shell vacancy
D. An electron produced during pair production
C
What term describes the reduction of photon intensity as it passes through matter?
A. Absorption
B. Scattering
C. Attenuation
D. Ionization
C
What is the half-value layer (HVL)?
A. The time it takes for half of the radioactive atoms in a sample to decay
B. The thickness of an absorber required to reduce the intensity of a photon beam by half
C. The energy required to remove an electron from an atom
D. The distance a charged particle travels through matter before losing all of its energy
B
In a gas detector, what type of particles move towards the cathode?
A. Electrons
B. Positive ions
C. Neutrons
D. Photons
B
What is the term for the region in a gas detector's voltage response curve where ions and electrons recombine, resulting in no current?
A. Ionization region
B. Proportional region
C. Geiger-Müller region
D. Recombination region
D
What is the Townsend avalanche?
A. A cascade of ionization events in a gas detector caused by high-energy electrons
B. The process of converting light photons into electrons in a PMT
C. The process of amplifying the electron signal in a PMT
D. The process of discriminating against background radiation in a PHA
A
What type of gas detector uses a high positive voltage on the center wire (anode) and a sealed chamber filled with a special gas mixture?
A. Ionization chamber
B. Proportional counter
C. Geiger-Müller counter
D. Dose calibrator
C
Why can't a Geiger-Müller counter distinguish between different energies of radiation?
A. It produces a large electrical signal that overwhelms the electronics
B. It has a dead time that prevents it from counting all of the radiation events
C. The size of the electrical signal is constant, regardless of the energy of the radiation
D. It is only sensitive to a narrow range of energies
C
What converts the energy of gamma rays into light in a scintillation detector?
A. Photocathode
B. Dynodes
C. Anode
D. Crystal
D
What component of a scintillation detector amplifies the electron pulse by millions?
A. Preamplifier
B. Amplifier
C. Photomultiplier tube (PMT)
D. Pulse height analyzer
C
What does the term "carrier-free" mean in relation to radionuclides?
A. The radionuclide is not attached to any other molecules
B. The radionuclide is not contaminated with any other radioactive isotopes
C. The radionuclide does not contain any stable isotopes of the same element
D. The radionuclide is transported without any packaging material
C
What is the process of splitting atoms using neutron bombardment called?
A. Fission
B. Fusion
C. Cyclotron acceleration
D. Generator production
A
What is the purpose of the control rods in a nuclear reactor?
A. To accelerate the neutrons
B. To absorb neutrons and control the rate of the nuclear reaction
C. To cool the reactor core
D. To shield the reactor from the environment
B
What is the term for the creation of an elementary particle and its antiparticle when a photon interacts with a nucleus?
A. Photoelectric effect
B. Compton scattering
C. Pair production
D. Bremsstrahlung radiation
C
What type of particle accelerator uses electromagnetic fields to propel charged particles to high speeds and is often used for the production of PET isotopes?
A. Linear accelerator
B. Synchrotron
C. Cyclotron
D. Betatron
C