Scott's test Ch 14

What are the 5 types of photon interactions?

Identify interaction
The incident photon is low energy

This interaction does not ionize the atom

The incident photon is absorbed in the region

The atom re emits a second photon of same energy as the incident photon, but is headed in new direction

This interaction does not have enough energy to cause release of any electrons

What is the most common interaction

Incident photon interacts with outer shell electron

A loosely bound electron in the  outer shell

Why is it called a 'free electron'

During which interaction does the the free electron absorb some of the photons energy and is ejected from the pouter shell making an angle with the direction of the incident photon

The photon is scattered from its incident path and has different energy and wavelength than the incident photon

what are 3 examples showing the effect of angle on the results of a Compton ( incoherent) interaction?

This angle results in the the Compton electron going straight forward carrying away most of the energy with the scattered photon traveling backward with a minimum amount of energy known as 'backscatter'

This angle results in  very little energy loss. Most energy is carried away by scattered photon which will have nearly the same energy as the incident photon

This angle is important of radiation protection purposes.

The energy of the photon at this angle reaches a maximum of .511MeV and is independent of the energy of the incident photon even at high energies

This interaction occurs at high energies

1.022 MeV MUST be the energy of the incident photon in order for this interaction to occur

The incident photon passes close to the nucleus of the atom

The incident photon is absorbed by the nucleus in this interaction

During this interaction, energy is re emitted as an electron -positron pair β-,β+, which is ejected from the atom

The rest energy of the electron- positron pair is_____

Electron positron pair production can also occur under the influence of the EM field of the electrons in the target material and is called ____ _______

This interaction involves directly hitting the nucleus of the atom and is absorbed

Energy is absorbed by the atom during which interactions

The sudden absorption of this energy causes the nucleus to emit both neutrons and gamma rays

Mainly occurs in high Z ( atomic number/protons)materials

Unimportant interaction in tissue (low Z)

Extremely important when working with accelerators or machines with hogher than 10MeV

Most radiation therapy energies fall into 1-5MeV
where this interaction predominates

Interaction which occurs below 1MeV

Interaction which occurs above 4.0 MeV

when the collision of material leads to excitation and ionization of the atoms,resulting in an interaction of charged particles with the nuclei leading to a radiative energy loss through the process of

Energy in motion through space

When on kinetic energy is lost during a collision it is described as a/an________ collision

When kinetic energy is lost from the system , the collision is ________

What are the 3 types of Electron interactions

Brehmsstrahulng occurs during this interaction

What is the most important method of producing xray beams in therapy units/