Physics Ch 14 Interactions

Name the interaction:

Name the interaction:

Name the interaction:

Name the interaction:

Name the interaction:

This consists of two neutrons & two protons bound together:
(equivalent to a helium atom that has been stripped of its two electrons)

What is the origin of gamma rays (γ)?

What is the origin of x-rays?

A _________ particle is the same as an electron, but with a different origin

Coherent (Thompson) scattering primarily occurs at energies below ______.

The result of Coherent scattering is to change the ________ of the incident photon without changing its ________.

X-rays scattered back in the direction of the incident x-ray are called __________ radiation.

The probability of Compton scattering ________ as x-ray energy ________.

The ________ is total x-ray absorption.

An x-ray with less than _____ (energy) cannot undergo Pair Production.

The process by which the positron unites with a free electron and the mass of both particles is converted to energy:

As the number of protons grows larger, the _______ (more/less) neutrons are required to maintain stability.

Cobalt 60 decays by ______ decay to an excited state of _______.

Large, unstable atoms that have a large amount of excess energy tend to undergo radioactive decay by the emission of ___________.

During β- decay, this particle carries away the energy that is left over when the β- does not carry away all of the atom's excess energy:

When a particle identical to an electron is emitted as a result of nuclear decay:

In β+ decay  the remainder of energy is carried away by the:

A subatomic particle that has exactly the same characteristics as an electron, except that it has a positive electrical charge:

When a positron is ejected from an atomic nucleus, a nuclear proton decays into a neutron and a positron:

When an electron strays too close to the nucleus, it can be captured and combined with a proton, reversing the process for β- decay:

Both _______ and _______ result in the Z of the parent nucleus being decreased by 1 and the ^N/_Z ratio of the atom increases

Because of the proximity of the _____ shell to the nucleus, it is most likely that the captured electron will be taken from this shell, although it is possible to capture an electron from those farther away.

This type of radiation is a result of when an electron is taken from its shell, leaving a "hole" in the shell, thus placing the atom in an unstable configuration; then an electron from a higher shell to fall/cascade to a lower shell and losing energy in the form of an x-ray to become stable

This represents a daughter product of some other kind of decay that is itself in an excited state, but instead of instantly decaying by gamma ray (γ) emission, it remains in this excited state for a given period of time & then decays.

An isomer (identical Z and A of another atom) is said to be in this state:

The amount of radioactivity present in a sample is never a constant quantity but rather is being reduced continuously by the decay of the radioactive atoms in the sample. This decay process follows a mathematical pattern know as

The time period in which the activity decays to one half the original value:

Thickness of absorbing material necessary to reduce the x-ray intensity to half its original value.

The average lifetime for the decay of radioactive  atoms:

A beam is called "______ intensity" if it has just a few photons per square centimeter, even if the photons are very high energy.

A beam is called " ______ intensity" if it consists  of a large number of photons, even if they are very low-energy photons.

Removal of photos & electrons from a beam by scatter or absorption as it travels through a medium, typically tissue or tissue equivalent materials.

Half-value layer values are defined by the _______ of the beam and the _________.

What is this used to determine:

Photon beams can be classified as "hard" or "soft" beams depending on their ______.

The effect of passing the beam through a lead attenuator to increase the overall HVL of the beam even though the intensity of the beam has probably been decreased:

Filtration that is built in to the machine:

In this interaction, the incident photon will change direction without losing any energy.

The probability of of various photon interactions with the atomic electrons & nuclei of the target depends on  the _______ of the photon and the __________ of the target material.

___________ is the thickness of the attenuator that reduces the beam intensity to 10% of its initial value.

Name the interaction in which the incident photon is absorbed but lacks sufficient energy to ionize so the atom re-emits a photon of identical energy but in a different direction:

Name the interaction in which the incident photon interacts the inner electron shells of an atom and an Auger electron is ejected:

Which interaction produces characteristic radiation:

Which interaction occurs primarily at energies below 10 KeV:

What is the photon interaction that is most commonly witnessed in the energy ranges used in radiation therapy (1-5 MeV)?

Which interaction occurs primarily at energies less than 1 MeV:

Which interaction is most commonly witnessed in diagnostic x-ray:

Name the interaction in which the incident photon interacts with free (outer) electrons and ejects an electron:

Which interaction produces back-scatter?

Name the interaction in which the incident photon passes close to the nucleus, is absorbed & instantly the energy is re-emitted as an electron-positron pair (β- , β+):

The pair production interaction is physically impossible when the energy of the incident photon is less than __________

What is the energy of each the electron-positron pair (the result of pair production)

Name the interaction in which the incident photon passes close to the nucleus:

Name the interaction in which the incident photon strikes the nucleus:

Name the interaction in which the incident photon strikes the nucleus, is absorbed and then the atom emits both neutrons and gamma rays (γ rays) in an attempt to maintain stability:

Which interaction occurs mainly in high Z materials and at higher energies?

Which interaction can result in triplet production?

Characteristic radiation and Auger electrons are emitted/ejected from the ________ while gamma rays are emitted from the ________.

In which photon interaction(s) does the incident photon lose all of its energy?

Which photon interactions ionize the atom?

Which interactions do NOT ionize the atom?

What is the most important method of x-ray production in therapy machines?

Electrons lose approx ______ per cm of travel in water.

The Law of Bergonie and Tribondeau states that ionizing radiation is more effective against cells that are:
(3)

Arrange the cell types in order of radiosensitivity most to least:
FPM
MCT
DIM
RPM
VIM

During which phase of cellular mitosis are cells most and least radiosensitive?