transmitted energy in the form of EM waves, charged and neutral particles from different sources such as the sun and atoms
involves the use of ionizing radiation that can ionize the medium it passes through, to deliver the lethal dose to the target cells while keeping normal tissue below tolerance level as much as possible.
Name 5 types of ionizing radiation sources produces by accelerators and radioactive sources
X-rays, gamma rays, and
electron, proton and neutron beams
Four Major quantities important to Radiation Physics
radiation absorbed dose
radiation dose equivalent
physical quantities are characterized by _____ and _____
magnitude and unit
The rate of change of position given by the ratio of Distance /time
According to SI units, the 7 basic physical quantities and their units are
Length (l) : meter (m)
Mass (m) : kilogram (kg)
Time (t) : second (s)
Electrical current (I) : ampere(A)
Temperature (T) : kelvin (k)
Amount of substance : mole (mol)
Luminous intensity : candela (cd)
smallest unit of an element which retains the properties of that element
What are subatomic atoms?
the electrons, protons and neutrons of an atom
elementary particles belonging to class of particles known as leptons
Composite particles belonging to class of particles known as Hadrons
neutrons and protons
Who is J.J. thompson?
Discovered electrons in 1897
The sub atomic particles are classify in two groups, the _______ and the _______
leptons and hadrons
Name the 4 types of forces which are responsible for the interaction between different particles
the Strong Force
the Weak Force
force responsible for interaction between electrically charged particles and particles with nonzero magnetic moments.
responsible for binding of electrons and nucleus to forms atoms, binding of atoms to form molecules , binding of molecules to form liquids and solids.
force responsible for interaction between particles with nonzero mass and has infinite range
what is the Strong Force?
short ranged force that is responsible for interaction between neutron and proton and other particles belonging to the hadrons family
Define the weak force
short ranged force responsible for interaction between elementary particles involving neutrinos or antineutrinos.
also responsible for radioactive decay of a neutron to a proton, an electron and an antineutrino (beta decay)
what is beta decay?
radioactive decay of a neutron to a:
and an antineutrino
Rank forces in order of strength, 1-4
3. Weak Force
The Strong force affects which group of particles?
Which forces affect the Lepton particle group?
Weak force, EM force and gravity
Subatomic particles important in Rad therapy are (5)
electrons, positrons, protons, neutrons, photons
Rest mass refers to
mass (weight) of the particle when it is not moving
which properties of subatomic particles are important in Rad therapy
Rest mass and electrical charge
How is mass of subatomic particle measured?
atomic mass unit (amu)
1 amu=1.99x10-26/12kg= 1.66x 10-27kg
an electrical charge is
a fundamental property or character of subatomic particles which determines the strength of their gravitational interaction
1 inch = _____ cm?
1 Ci =
3.7 x 10 10 Bq
1 Bq =
2.7 x 10-11 Ci
1 roentgen (1 R) =
2.58 x 10-4 C/kg
1 Coulomb/ kilogram (1 C/kg) =
3.88 x 103R (roentgen)
1 rad =
1 Gy =
1 cGy =
1 curie 3.73 x 1010 dps Bq
1 Becqueral 2.7 x 10-11 Ci
Radiation Exposure (in air)
roentgen (R) 2.58 x 10-4 C/kg
Coulomb C/kg 3.88 x 103 R
Radiation Absorbed Dose
1 rad = .01 Gy
1 cGy = 1 Rad
1 Gy = 100 rad
Radiation Dose Equivalent
rem = .01 Sv
Sv = 100 rem
Atomic mass unit
defined as mass of an atom of carbon 12 is 12 amu
1 amu = 1.66 x 10-27kg
What is electrical charge?
a fundamental property or character of subatomic particles.
determines the strength of their EM interaction
What does the mass of the subatomic particles determine?
the strength of their gravitational interaction
What are the 4 assumptions of the Bohr atom?
1. Electrons surrounding the nucleus exist only in certain energy states.
2.Electrons do not lose energy when they reside in any of the allowed orbits.
3.when electrons move from a high energy orbit to a lower energy orbit the atom emits radiation. the lost energy is seen in the atomic spectra.