Rad Protection exam 2

Direct interactions include

Coherent/Classical/Thompson, Compton, and Photoelectric

Indirect Interactions include

Radiolysis of water

Interactions not in our range include

Pair production and photo desentigration

In the EM spectrum, X=

50-120 kEV energy

Coherent/Classical/Thompson has the __________ energy range for interactions

lowest

Coherent/Classical/Thompson can

cause fog or expose patients/techs

Coherent/Classical/Thompson the first step is

IP interacts with an electron (not a specific shell)

Coherent/Classical/Thompson the second step is

IP energy is always less than the binding energy of the electron

Coherent/Classical/Thompson the third step is

There is no ionization

Coherent/Classical/Thompson the fourth step is

The electron absorbs the energy of the photon and then immediately puts off a secondary photon in another direction of like energy

Coherent/Classical/Thompson the equation is

IP=SP

Compton Interaction is responsible for

the majority of the fog(from scatter) on our image and the majority of tech exposure due to scatter hitting the tech

In compton interaction the NCRP guideline states that a scatter photon must go through 2 interactions before hitting the tech and that each interaction will

decrease origional intensity of a photon by 1000 unless lead shielding is used

In compton interaction the first step is

IP will interact with outer shell electron

In compton interaction the second step is

IP energy is greater than binding energy of electron

In compton interaction the third step is

Electron is dislodged and we now have a possitive ion (ionization)

In compton interaction the fourth step is

A recoil electron emerges from the atom/shell

In compton interaction the fifth step is

IP will contimue at a lower energy which is a scatter photon (the majority of energy left is held by this scatter photon)

In compton interaction the disloged electron is called the

recoil electron

Compton occurs accross the

entire spectrum

In compton interaction the equation is

IP= binding energy of e- + kinetic energy of recoil e- + energy of scatter photon

Photo electric interaction is responsible for

the majority of contract on our image and the majority of patient injury of the direct interactions

Photo Electric interaction the first step of the first part is

IP will interact with an inner shell electron

Photo Electric interaction the 2nd step of the first part is

We have ionization

Photo Electric interaction the third step of the first part is

All of the engery of IP is absorbed into the e-

Photo Electric interaction the fourth step of the first part is

The photon electron will travel at a kinectic energy equal to IP-BE of e-

Photo Electric interaction the fifth step of the first part is

PE is essentially a tiny bullet and can cause injury such as main chain scission

Photo Electric interaction the equation is

IP=Binding energy + kinetic energy of PE

Photo Electric interaction in the second part

an atom must stabilize itself

Photo Electric interaction the first step of the second part is

If ionized an e- (+ ion) will be drawn in to fill the hole where the ejected e- was

Photo Electric interaction the second step of the second part is

e- will drop from one shell to another

Photo Electric interaction the third step of the second part is

when this happens a “characteristic photon“ is released by the atom that is “characteristic“ to the difference between the two binding energies

Photo Electric interaction the fourth step of the second part is

when we have a hole in the valance the atom can now draw in an e- to stabilize