RAD 102 Exam 2

True or False: Heavy charged particles transfer energy to the target low Z medium through coulomb collisions and Bremsstrahlung radiation equally.

False

True or False: Positrons and negatrons with the same kinetic energy have essentially the same range in matter.

True

True or False: Neutrons primarily interact with an atom's electron cloud while photons primarily interact with the atom's nucleus.

False

True or False: If 0.5 mm of lead is sufficient to reduce the incident photon beam to ½ its initial intensity, then 1.0 mm of lead will be enough to completely stop the beam.

False

True or False: Indirectly ionizing radiation must cause a chemical interaction to produce an ion pair.

False

True or False: As heavy charge particles slow down, their stopping power increases, resulting in more energy loss at the end of its path and a "Bragg Peak".

True

True or False: X-rays and gamma rays are identical in every way except for the processes that create the photons (atomic vs. nuclear processes)

True

True or False: The shielding provided by dosimeters is an essential part of your company's radiation safety program. As such, your dosimeter must be worn in the correct location, indicated on the badge, at all times while using radioactive materials or sources.

False

True or False: Cancer patients represent a significant population that has been exposed to large doses of ionizing radiation, making them the most significant source of data on the risk of cancer due to exposure to ionizing radiation.

False

True or False: Heritable effects, or radiation-induce mutations passed on to offspring of the exposed individuals, were observed to increase in the survivors of the atomic bomb explosions in Japan.

False

True or False: Less than 30% of those exposed to the LD50/30 dose are expected to survive without medical intervention

False

True or False: Generally speaking, alpha emitting radioactive material is only harmful if it is inside the body.

True

True or False: The pathlength of an electron will always be greater than its range.

True

"A photon interacts with an atomic electron, transferring a portion of its energy to the electron before continuing on through the target material with a longer wavelength" best describes what interaction mechanism?

a) Photonuclear Reaction

b) Photoelectric Effect

c) Pair Production

d) Compton Scattering

d) Compton Scattering

Ionizing radiation transfers energy to the target atom(s), causing __ ?

a) excitation of electrons with x-ray emissions and/or ionization of atoms.

b) the formation of proton/electron pairs.

c) emission of conversion electrons

d) electron scattering and annihilation

a) excitation of electrons with x-ray emissions and/or ionization of atoms

Electrons, or light charged particles, interact

a) Indirectly with matter through capture reactions, producing electrons which cause further ionization or excitation in the target medium.

b) Indirectly with matter, creating ionizations by "stealing" electrons from the neutral atoms in the target medium

c) Directly with matter, losing energy through thousands of small Coulomb collisions

d) Directly with matter, losing energy through coulomb interactions and Bremsstrahlung (radiative) processes

d) directly with matter, losing energy through coulomb interactions and Bremsstrahlung (radiative) processes

Excited atoms are best described as ______?

a) Atoms with one (or more) missing electrons

b) Atoms with non-zero kinetic energy

c) Atoms with one (or more) extra electrons

d) Atoms with one (or more) electrons in a higher energy state

d) Atoms with one (or more) electrons in a higher energy state

Which of the following can be classified as directly ionizing radiation?

a) X-rays

b) Neutrons

c) Electrons

d) gamma rays

c) Electrons

If we want to produce more X-rays (in an X-ray machine for example), we should _____?

a) Decrease the energy of the electron beam (the tube voltage).

b) Use a thicker target (increase mass of the target material)

c) Use a low-Z material (like aluminum) as the electron target.

d) Use a high-Z material (like tungsten) as the electron target.

d) use a high-Z material (like tungsten) as the electron target

The stopping power of a material is defined as

a) The inverse of the range of the charged particle in the material (high stopping power = shorter range)

b) The probability of a collision per unit distance pathlength

c) The average energy lost by the particle per unit distance travelled

d) The average energy transferred to the target material per collision

c) the average energy lost by the particle per unit distance travelled

_________ is the probability of a photon interacting with matter per unit distance.

a) Gamma Interaction coefficient

b) Cross section

c) Linear attenuation coefficient

d) Stopping power

c) linear attenuation coefficient

For diagnostic applications (less than 100 keV) in tissue, what is the most common interaction mechanism?

a) Annihilation

b) Photoelectric Effect

c) Pair Production

d) Compton Scattering

b) photoelectric effect

Which of the following particles would be expected to be able to penetrate the skin, but would not be expected to impact internal organs (a range of a few cm)?

a) Alpha particles

b) Electrons

c) 120 keV X-rays

d) Protons

b) electrons

If you want to reduce your exposure to an X-ray source by at least a factor of 10, how much shielding would be most appropriate to use?

a) An apron providing 4 HVL lead equivalent

b) An apron providing 2 HVL lead equivalent

c) An apron providing 8 HVL lead equivalent

d) An apron providing 1 HVL lead equivalent

a) an apron providing 4 HVL lead equivalent

If you want to reduce your exposure from an X-ray source to zero, how much shielding would you need?

a) 10 HVL

b) 2 HVL

c) 4 HVL

d) Theoretically, shielding can never completely reduce the exposure to zero

d) theoretically, shielding can never completely reduce the exposure to zero

Radiation interacts with matter, transferring energy to the target medium causing

a) Conversion electrons and annihilation photons

b) Ionizations and excitation of atoms

c) Nuclear reactions and gamma emissions

d) A warm, fuzzy feeling

b) ionizations and excitation of atoms

Which of the following best describes a gas-filled detector, such as an ionization chamber?

a) A cylinder filled with an inert gas with a voltage applied across it. Ionization in the gas produces free electrons, which are collected on the anode, resulting in a current signal.

b) A tube filled with a transparent gas attached to a photomultiplier tube. Excitation in the gas causes the emission of light, which is multiplied and converted to a signal.

c) A tube filled with a gas under very high voltage. The voltage is set high enough to strip electrons off the molecules, creating a plasma. Ionizing radiation transfers energy to the charged gas plasma through Coulomb interactions, generating a signal.

d) A cylinder filled with an inert gas under very high pressures . . . pressure transducer.

a) A cylinder filled with an inert gas with a voltage applied across it. Ionization in the gas produces free electrons, which are collected on the anode, resulting in a current signal.

A device worn on a person that assesses the amount of radiation received is called a:

a) Gas detector

b) Dosimeter

c) Scintillation detector

d) Geiger-Meuller (GM) detector

b) dosimeter

Which type of detector converts the energy deposited in the detector to light, which is then measured and converted to the detection signal?

a) All of the above

b) Scintillation detectors

c) Solid-state detectors

d) Gas-filled detectors (GM detector, ion chamber, etc.)

e) Radiographic film or film badges

b) scinillation detectors

The difference between CPM and DPM is:

a) That CPM accounts for the potential biological damage that the radiation would cause if absorbed in living tissue while DPM measures just the energy deposited in the detector.

b) CPM is used for detectors that are not calibrated, while DPM is used for the output of calibrated detector systems.

c) There is no difference. 1 CPM = 1 DPM

d) That CPM is the number of events observed by the detector, while DPM is the number of decays/events that actually occurred.

d) That CPM is the number of events observed by the detector, while DPM is the number of decays/events that actually occurred.

Why do we need an image intensifier for X-ray systems using film?

a) An intensifier is needed to fix the silver as a metal after it reacts with the ionizing radiation, creating a clearer image for the negative

b) An intensifier is needed because the film is not sensitive to radiation at short wavelengths

c) An intensifier is needed to decrease the image "fog" caused by scattered photons

d) An intensifier isn't necessary to cause an image from radiation exposure. However, without an intensifier screen, the dose required to get a good image increases significantly.

d) An intensifier isn't necessary to cause an image from radiation exposure. However, without an intensifier screen, the dose required to get a good image increases significantly.

Which of the following is NOT true about OSL badges issued for dosimetry?

a) Dosimeter badges are an essential part of a radiation safety program, allowing exposures to radiation to be measured to ensure compliance with regulatory limits.

b) Dosimeter badges are an essential part of a radiation safety program, providing additional shielding to reduce worker exposure to radiation

c) Dosimeter badges can measure fairly small exposures even in states with higher natural background radiation.

d) Dosimeter badges are legally protected in some states as part of a state-regulated safety program. Intentionally tampering with dosimetry can result in felony charges in NV (for example).

b) Dosimeter badges are an essential part of a radiation safety program, providing additional shielding to reduce worker exposure to radiation

Indirect damage to DNA is the term used to describe

a) Damage caused to DNA by the misrepair of double-strand breaks caused by ionizing radiation

b) Damage to DNA by indirectly ionizing radiation, like photons and neutrons

c) Damage caused to DNA by radiation-induced damage in neighboring cells

d) Damage caused to DNA by free radicals created by radiolysis of water in the cell

d) Damage caused to DNA by free radicals created by radiolysis of water in the cell

The primary stochastic effects of exposure to ionizing radiation are increased risk of cancer and

a) Decreased immune response (hemopoetic syndrome)

b) Decreased life expectancy (life shortening)

c) Increased risk of heritable defects

d) Increased risk of Alzheimer's disease

b) Decreased life expectancy (life shortening)

Which of the following best describes the dose-response for a stochastic effect?

a) Above a minimum threshold, the mortality (probability of death) is observed to increase as dose increases

b) As dose increases, the severity of the effect increases.

c) As the dose increases, the probability of an effect manifesting increases.

d) As the dose increases, the latency time (time between exposure and effect manifesting) decreases

c) As the dose increases, the probability of an effect manifesting increases.

Which of the following best describes the dose-response for a deterministic effect?

a) As the dose increases, the probability of an effect manifesting increases.

b) As the dose increases, the latency time (time between exposure and effect manifesting) decreases

c) Above a minimum threshold, the mortality (probability of death) is observed to increase as dose increases

d) As dose increases, the severity of the effect increases.

d) as dose increases, severity of the effect increases

For acute radiation sickness, which of the following lists the ARS syndromes in order of threshold or initiation dose (from lowest to highest)

a) Central Nervous Syndrome/Neurovascular, Hematopoietic, Gastrointestinal

b) Gastrointestinal (GI), Hematopoietic, Neurovascular / Central Nervous (NV or CNS)

c) Hematopoietic, Gastrointestinal, Central Nervous Syndrome/Neurovascular

d) Sterility, Epilation, Skin Erythema

e) None of the above

c) Hematopoietic, Gastrointestinal, Central Nervous Syndrome/Neurovascular

Ionizing radiation is observed to be teratogenic, which means

a) exposure of the reproductive system can result in decreased sperm count and temporary or even permanent sterility

b) all of the above

c) exposure to a fetus/embryo can result in significant effects, including birth defects and termination of the pregnancy

d) exposure of the sperm/ova can result in genetic damage passed on to offspring

c) exposure to a fetus/embryo can result in significant effects, including birth defects and termination of the pregnancy

For a 1 Ci sample, 137Cs has a larger half-life than radionuclide 60Co. Which has a larger decay constant?

a) 60Co

b) 137Cs

c) Impossible to know without more information, such as the atomic weight

d) Decay constant is the same since the mass is the same

a) 60Co

32P emits a 1.71 MeV beta. The best shield material for 32P waste is:

a) Water

b) Paper

c) Plexiglas (plastic)

d) Lead

c) Plexiglas (plastic)

For stochastic, or chronic, effects, which of the following best describes the latency of the effect

a) Stochastic effects become evident years to decades following exposure

b) Stochastic effects become evident within days to weeks following exposure

c) Stochastic effects become evident within microseconds of exposure

d) Stochastic effects become evident within hours to days following exposure

a) Stochastic effects become evident years to decades following exposure

The best shield for neutrons is:

a) Lead

b) Water

c) Paper

d) Plexiglas (plastic)

b) Water

Which material would make the best shielded beta emitting rad waste container?

a) Aluminum

b) Plexiglass

c) Paper

d) Lead

b) plexiglass

You have a high-energy beta emitting source. You can use steel or aluminum to shield the source. Which of the following statements are most true?

a) The betas will interact with the aluminum to produce gamma rays.

b) An aluminun shield would increase the number x-rays outside the container.

c) Steel would increase the number of x-rays outside the shield.

d) Steel would be a better beta shield.

c) Steel would increase the number of x-rays outside the shield.

Match the source to what you do with it. One answer for each. No repeats.

Neutron ---- Double shielding with HDPE and Lead

Photon ---- Lead pig container

Beta ---- Put in pocket

Alpha ---- Hold in hand

Neutron ---- Double shielding with HDPE and Lead

Photon ---- Lead pig container

Beta ---- Put in pocket

Alpha ---- Hold in hand

The picture below shows an analog meter of the G-M counter. What is the possible reading in the picture?

a) 1.6K Bq

b) 5mR/h

c) 1.6K CPM

d) 0.5mR/h

b) 5 mR/h

Exposure is

a) The amount of charge (of one sign) produced in air by x-rays or gamma rays

b) The dose received by the patient (or technician) from ionizing radiation, like x-rays

c) The amount of blackening caused in irradiated film or imaging systems

d) The energy absorbed by biological tissue from ionizing radiation

a) the amount of charge (of one sign) produced in air by x-rays or gamma rays

In 1905, ________________ proposed a theory of the photoelectric effect using a concept first put forward by Max Planck that light consists of tiny packets of energy known as photons. He also discovered the relationship between energy and mass, which is E = mc2.

a) Louis de Broglie

b) Max Planck

c) Albert Einstein

d) Arthur Compton

c) albert einstein

In the detectors below, one of them uses an entirely different principle. It is

a) Geiger counter

b) Ionization chamber

c) Cerenkov counter

d) Proportional counter

c) cerenkov counter

See the plot below (unit length is cm). An electron traveled in some kind of matter. The starting point was O(0,0). It passed through A (7,3), B (-5,7), C (-2, -6), and finally stopped at D (2,-3). The total pathlength is _______________ cm.

a) 66.6

b) 38.6

c) 56.6

d) 47.6

b) 38.6

See the plot below (unit length is cm), the range of this electron in the matter is ___________________ cm.

a) 8.60

b) 7.62

c) 9.06

d) 8.06

a) 8.60

According to the figure below, indicate which of the three major interaction processes (Photoelectric Effect, Compton Scattering, Pair Production) is dominant in the following situations:

100 keV gamma rays in iron: Photoelectric Effect

Correct!1 MeV gamma rays in aluminum: Compton Scattering

Correct!10 MeV gamma rays in lead: Pair Production

100 keV gamma rays in iron: Photoelectric Effect

Correct!1 MeV gamma rays in aluminum: Compton Scattering

Correct!10 MeV gamma rays in lead: Pair Production

A ____________ ray is a secondary electron with enough energy to escape a significant distance away from the primary radiation and produce further ionization.

a) beta (B)

b) gamma (y)

c) delta (&)

d) alpha (a)

c) delta (&)

In the dose-response curves below, the less fatal effects, such as skin erythema and cataract, follow the _____________ curve.

a) Linear, no threshold

b) Linear

c) Sigmoidal

d) Curvilinear

b) linear

Which of the following is not a nuclear accident?

a) Three Miles Island

b) Chernobyl

c) Fukushima Daiichi

d) Boeing 737 Max

d) Boeing 737 Maax

The Radium Girls were female factory workers who contracted radiation poisoning from painting watch dials with self-luminous paint. The women in each facility had been told the paint was harmless and subsequently ingested deadly amounts of _____________ after being instructed to "point" their brushes on their lips in order to give them a fine tip; some also painted their fingernails, face, and teeth with the glowing substance.

a) Uranium

b) Radium

c) Cs-137

d) I-131

b) radium