NM 112 - Units of Measurement and Conversions

Will also include updated definitions and explanations on the 5 types of radiation decay's

Radiation

The emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization

What are the 2 types of energy that radiation can take the form of?

1. Just energy

2. Particles with energy

What are the 2 main energy radiation?

X-ray and Gamma ray

What are the 2 main particulate energies?

alpha and beta

Alpha Decay (updated information)

Has a nucleus that is too unstable with too many protons and neutrons. Will expel excess via a Helium nucleus (alpha particle that contains 2 protons and 2 neutrons only)

What is the charge of an alpha particle?

a +2 charge due to the protons

Beta minus (updated information)

Nucleus has too many neutrons, will convert one into a proton and create an electron (beta -) as a byproduct for balance of charge within nucleus

What happens to the negatron after it’s been made as a byproduct?

Negatron is made and remains outside of the nucleus until it runs out of energy and converts back into an electron (e-)

Beta positive (updated information)

Nucleus has too many protons, will convert one into a neutron and will create a neutron and also create an electron (beta +) as a byproduct for charge balance

Can a positron exist in nature? What happens to it after it’s been made?

Positron cannot exist in nature. It will naturally get annihilated after it has used up all its energy — converting back into an e+ — will meet an e- and annihilate each other.

What is created from the annihilation of an e+ and an e-?

Annihilation of the electrons will emit a gamma ray that is used in PET imaging.

Electron capture (updated information)

A nucleus has too many protons but it doesn’t have enough energy to undergo positron emission. It will instead pull energy from the nearest electron shell via electrons mass. Proton and new electron will interact and create a neutron

What happens to the electron shells during electron capture?

Pulling an electron from nearest electron shell will leave a vacancy. Vacancy is filled by surrounding outer shells. Movement of outer shell into vacant spot will emit an energy similar to an x-ray.

Gamma emission (updated information)

High energy atom that is unstable due to nucleus having a high amount of excess energy. Excess energy is emitted out as a gamma ray

What is gamma emission be a result of for a certain decay process?

Can be resulted from beta minus decay as the daughter is left in an excited state from excess energy

What is the speed that energy moves in on the electromagnetic spectrum?

Is moving in the speed of light

What determines the energy’s frequency?

Determined by the size of the energies wavelength

How are all the energies on the electromagnetic spectrum related?

All of the energies displayed on the spectrum are of the same energy and all are moving at the same speed of light.

How are all the energies on the electromagnetic spectrum different from one another?

They differ in their energies, frequencies, and length of their wavelengths

Are gamma rays always in higher energy than x-rays?

Gamma rays are not always in higher energy than x-rays. Some x-ray’s will be higher than gamma ray’s and it’s better to say that the two overlap.

The nucleus of the x-ray’s have the potential for energy but doesn’t always have more energy.

What are the 2 units to measure energy?

keV and MeV

What are the 2 units to measure radioactivity?

Curie (Ci) and Becquerel (Bq)

What are the 2 units to measure exposure?

Roentgen (R) and C/kg

What are the 2 units to measure for equivalent dose?

REM and Sievert (Sv)

What does it mean to measure for exposure?

Observes how many ionizations occur in all molecules per unit of time via the electrons that are present in the air

Evaluates and/or characterizes radiation

Ionization

When radiation comes in and “hits” an air molecule, the electron is lost and the gas molecule becomes positively charged

What is the common conversion factor used to measure exposure?

1 R = 2.58 × 10^-4 C/kg

What does it mean to measure for absorbed dose?

Describes how much radiation was absorbed in the patient’s body

However, it doesn’t take into consideration the type of radiation that was used

What is the common conversion factor used to measure absorbed dose?

1 Gray = 100 rad

What does it mean to measure for the equivalent dose?

Measurement recognizes the different types of radiation but takes the absorbed dose and makes it the equivalent

Comparing the radiation of one energy (alpha, beta, gamma) to another

What is the common conversion factor used to measure for equivalent dose?

1 Sv = 100 REM

Where does the energy from x-ray’s come from?

Comes from the electrons

Where does the energy from gamma ray’s come from?

Comes from the nucleus

What are the 2 units used to measure absorbed dose?

Gray and RAD

What is the common conversion factor used to measure for absorbed dose?

1 Gray = 100 RAD