biophysics

Mass

the amount of matter in an object

Weight

the force of gravity on an object

Energy

the ability to do work

electromagnetic radiation

Radiation that has both electric and magnetic fields. Ex: X-Ray

potential energy

stored energy that results from the position or shape of an object

kinetic energy

the energy an object has due to its motion

chemical energy

A form of potential energy that is stored in chemical bonds between atoms.

electrical energy

Energy caused by the movement of electrons.

thermal energy

Heat energy

nuclear energy

Energy stored in the nucleus of an atom

The shorter the Photon wavelength.....

greater the photon energy

electromagnetic spectrum

All of the frequencies or wavelengths of electromagnetic radiation

radio waves

Electromagnetic waves with the longest wavelengths and lowest frequencies.

microwaves

Electromagnetic waves that have shorter wavelengths and higher frequencies than radio waves.

infared waves

Wavelengths that are long can be detected as heat.

visible light

Electromagnetic radiation that can be seen with the unaided eye

X-rays and gamma rays

Both used for medical imaging

ionizing radiation

radiation with enough energy to knock electrons off some atoms of a bombarded substance to produce ions

Electromagnetic energy

is a field or state of energy which exists over a wide range of magnitude called energy continuum

Photon

The smallest quantity of any type of electromagnetic radiation traveling through space at the speed of light. Have no mass but have electric and magnetic fields that are continuously changing in sinusoidal fashion

Wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Frequency

the number of complete wavelengths that pass a point in a given time

time period

1/frequency

Amplitude

Height of a wave

Vectors

quantities that have both a magnitude and a direction

Electrostatics

the study of electric charges that can be collected and held in one place

Inductance

Generation of magnetic fields

Electrodynamics

The study of electric charges in motion

Capacitance

Generation of electric fields

Resistance

Generation of heat

magnetic domain

The smallest region of magnetism

Magnetic susceptibility

Is the extent to which a material becomes magnetized when placed in magnetic field

Unit of electrical charge

Coulomb (C)

charge of a single electron or proton

Plus/minus 1.6x10^-19 c

electrical current

is a flow of electric charge.

Symbol of Magnetic Field

B

unit of magnetic field

Tesla (T)

1 Tesla \= \______ Gauss

10,000

permanet magnet

a magnet that retains its magnetic properties in the absence of an inducing field or current.

Resistive magnet

a magnet that can be turned on and off, and uses the principles of electromagnetism to generate a magnetic field

superconducting magnets

Electromagnets that use special cores that are kept at an extremely low temperature to reduce resistance, producing a stronger magnetic field.

Anode

is the positive side of the x-ray tube

two types of anodes

stationary and rotating

Scattering

causing a deflection of the energy out of the original beam direction

Absorption of x-rays

A beam of x-rays passing through matter is weakened and gradually disappears

Attenuation of X-Rays

The reduction of X-ray intensity as they pass through matter.

classical scattering

is an interaction between low-energy x-rays and atoms, the x-rays loses no energy but changes direction slightly. The wavelength of the incident x-ray is equal to the wavelength of the scattered x-ray

Compton effect

Occur between moderate energy x-ray and outer-shell electrons. it results in ionization of the target atom, change in photon direction, and reduction of photon energy. the wavelength of scattered x ray is greater than that of the incident x ray

photoelectric effect

occur when an incident x ray is totally absorbed during the ionization of an inner-shell electron. the incident photon disappears, and the k-shell electron, now called a photo-electron, is ejected from the atom

Pair production

occur with x rays that have energies greater than 1.02MeV. The photon interacts with nuclear force and tow electrons that have opposite electrostatic charge are created

Photodisintegration

is an interaction between high energy photon and the nucleus. The photon is absorbed by the nucleus, and a nuclear fragment is emitted

Rutherford

Who introduced the nuclear model (small dense positively charged center surrounding by a negative randomly located electrons)?

The orbital electrons revolved about the nucleus in prescribed shells or energy levels

What is the Bohr model of the atom?

Atoms may combine to form molecules and molecules may combine to form compounds

What is the combination of atoms?

Magnitude of matter

When is the power of ten notation necessary?

9\.1x10^-31kg

What is the mass of an electron?

2000

The proton and the neutron, both have nearly _____________________ times the mass of an electron

Empty

The atom is mostly ______________ space

0\.001% of the volume of an atom is occupied by matter

The size of the electron = the size of the nucleus therefore…..

K, L, M, N

What are the shells that makes up the outer electron shell configuration?

Eight

What is the maximum number of electrons an outer shell can contain?

The strength of attachment of an electron to the nucleus

What is Eb?

Atomic number Z

The number of protons is the….

Atomic Mass Number A

The number of protons plus neutrons is the….

Higher the Eb

The larger and more complex the atom the _______________________ for electron in an given shell

Radionuclides

What are atoms that involved Radioactive disintegration or radioactive decay to reach stability?

The net result of beta emission is to increase Z by one while A remains the same

What is Beta Emission?

Alpha particle consists of 2 protons and 2 neutrons. the nucleus of an atom becomes unstable (the ratio of neutrons to protons is too low) and alpha particles are emitted to restore balance

What is Alpha Emission?

Radioactive half-life

What is the period of time required for a quantity of radioactivity to be reduced to one half its original value?

Curies (Ci)

What is radioactive material measured in?

3\.7x10^10Bq

1 Ci= Bq?????

Beta and Alpha Emission

How do radioisotopes decay to stability?

Any subatomic particle in motion capable of causing ionization, electrons, protons, neutrons… rare nuclear fragments

What is Particular Radiation?

Equivalent to helium nucleus, 4-7MeV, specific ionization 40000 atoms/cm, in air travel 5 cm, in soft tissue 100um

What are some characteristics of Alpha Particle?

amn=0, carry one unit of -ve charge emitted from the nucleus, specific ionization> 100 ion pair/cm, travel in air 10-100 cm and 1 to 2 cm of soft tissue

What are some characteristics of Beta Particles?

1\.66x10^-27

1 amu = Kg???

The nuclei’s neutron-proton composition

Most Physical and chemical characteristics of a substance relate to ……

Nuclides that belong to the same chemical element but have different numbers of neutrons

What are isotopes?

Nuclides having the same mass number but different atomic numbers

What are Isobars?

Nuclei can have the same neutron-proton composition but not be identical; one nucleus can contain more energy than the other

What are Isomers?

Unstable, Radioactive/Metastable, Or Stable

What are the levels of Nuclear Stability?

Ratio of the number of neutrons to the number of protons. N/P ratio

What is the most significant factor that determines the balance between internal forces and therefore the nuclear stability?

Generally be radioactive

If the neutron-proton ratio is slightly above or below the ratio for stability, the nucleus will….

Emit Energy

whenever a nucleus changes to a more stable form it must?

MC^2

E=

6\.24x10^8

1 Erg = KeV??

6\.24x10^15

1 j= 10^7 Erg = KeV??

Nuclear mass change of 0.0001 amu to 0.0005 amu

E released in the radio active transitions used in NM, 100 KeV to 500 keV. this corresponds to a…

Energy is emitted as radiation (energetic particles or photons)

What happens in radioactive transitions?

Particle Radiation

What is a byproduct of radioactive transition required for desirable photon emissions?

Loss of energy and, possibly, a change in atomic number in a n isobaric transition

During radioactive transitions what happens within the nucleus?

Beta emission, Positron emission, and electron capture

What are the types of isobaric transitions?

The emission of energetic electrons, results when N/P ratio is too high for stability

What is beta radiation?

When N/P ratio is too low for stability

When do Positron emission or electron capture occur?

The number of protons, and therefore the atomic number, of the nucleus to increase by one unit. since the mass number, or total number of neutrons and protons, is not changed, the transition is isobaric

What does the emission of a beta particle cause?

Neutrino Energy

What is very penetrating and carries the energy out of the patient’s body?

Transition energy for the nuclide

In each transition, the sum of the beta and neutrino energy is equal to the….

Between 25% and 30% of the maximum energy

What is the average beta energy in nuclear medicine?

Positron

What is a small particle that has essentially the same mass as an electron but has a positive electrical charge?

Positron Emission

In this transition a proton is converted into a neutron as the positron particle is formed?