Charged Particles with Matter Flashcards
This refers to radiation with enough energy to knock an electron loose from an atom. A. Ionizing Radiation B. Collisions C. Ionization D. Secondary Ionization
Ionizing Radiation
True or False
Only a fraction of the particle’s energy can be transferred to an electron in an atom or molecule
True
True or False
A minimum of 100 eV is necessary to knock these electrons
True
As a particle transfers their energy, it slows down. Its energy is kinetic energy and kinetic energy is equal ________.
KE = ½ 𝑚𝑣^2
True or False
It slows down as it transfers energy. As kinetic energy decreases, velocity must also decrease, since mass remains constant.
True
Are often used to describe the transfer of energy from particle to atom. A. Ionizing Radiation B. Collisions C. Ionization D. Secondary Ionization
Collisions
The kinetic energy of the particle is cleanly transferred as kinetic energy to the electron.
Elastic Collision Exists.
This includes the conversion of the particle’s kinetic energy to some other form (electron moving to a higher energy shell). This is common between large charged particles (proton, alpha particle) and electron. A. Inelastic Collision B. Elastic Collision C. Primary Ionization D. Secondary Ionization
Inelastic Collision
This takes place if the amount of energy transferred by the particle is greater than the electron’s binding energy, the electron is removed from the atom. A. Ionizing Radiation B. Collisions C. Ionization D. Secondary Ionization
Ionization
The creation of an ion pair by ionizing radiation is called \_\_\_\_\_\_. A. Inelastic Collision B. Elastic Collision C. Primary Ionization D. Secondary Ionization
Primary Ionization
It is an atom with a deficiency of electrons (loses an electron).
Cation
It is an atom with an excess of electrons (gains an electron). A. Cation B. Anion C. Range D. Specific Ionization
Anion
Is formed by the freed (ionized) electron causing its own ionization due to its significant amount of kinetic energy. A. Inelastic Collision B. Elastic Collision C. Primary Ionization D. Secondary Ionization
Secondary Ionization
The freed electron is often called ______ or collectively known as _____–
Secondary Electron
Delta Rays
are roughly two times more common than ionization in air.
Electron excitations
As charged particles travels through matter, it creates number of ion pairs per unit length. Which is dependent on (a) energy of charged particle and (b) density of matter it is traveling through. A. Cation B. Anion C. Range D. Specific Ionization
Specific Ionization (SI)
True or False
The specific ionization of alpha particles traveling through air varies from 8 to 15 million ion pairs per meter (IP/m).
False - 3 to 7 million
Amount of energy deposited per unit path length is called ______
Linear Energy Transfer (LET)
True or False
LET of a charged particle is proportional to the square of the charge and inversely proportional to its kinetic energy.
True
Correct What makes the Sentence Wrong
Low LET radiations (alpha particles, protons, etc.) are more damaging to tissue than High LET radiations (electrons, gamma and x-rays).
High Let radiations are more damaging than Low Let radiations
It is defined as the average distance a charged particle will travel before being stopped. A. Cation B. Anion C. Range D. Specific Ionization
Range
For alpha particle and other heavy charged particles, range can be calculated by _______
dividing the energy of alpha particle (E) by its average linear energy transfer
(LET) R = E/LET
Alpha particle range (cm) in air can also be estimated solely from its energy using _____
Ra-air = 0.31 E^3/2 a
True or False
specific ionization and LET vary with the energy of the particle 40,768.09 IP/cm
True
It plots the energy loss of ionizing radiation during its travel through matter. This represents the fact that charged particles deposit much of their energy after penetrating matter some distance. The probability of interaction increases as the particle continues to decelerate. A. Path Length B. Multiple Scattering Events C. Ionization D. Bragg Peak
Bragg Peak
Electrons follow tortuous paths in matter as the result of\_\_\_\_\_\_\_\_. A. Path Length B. Multiple Scattering Events C. Ionization D. Bragg Peak
Multiple Scattering events
True or False
Charged particle results in dense and usually linear ionization track.
True
It is the actual distance particle travels.
Path Length
It is actual depth of penetration in matter. A. Cation B. Anion C. Range D. Specific Ionization
Range
Their high kinetic energy, positive charge and large mass compared to an electron, allows them to cause a great many ionizations in a very short travel distance. A. Annihilation B. Beta Particle Interaction C. Alpha Particle Interaction D. Neutron Interactions
Alpha Particle Interaction
True or False
Alpha particles are not easily shielded against and can be stopped by a single sheet of paper.
False - are easily shielded
It is much less massive and less charged than alpha particles and interact less intensely with atoms in the materials they pass through. A. Annihilation B. Beta Particle Interaction C. Alpha Particle Interaction D. Neutron Interactions
Beta Particle Interaction
True or False
High energy beta particles are not capable of penetrating the dead layer of the skin
False - Low energy
As the positron moves along, it pulls electrons out of the atoms and produces \_\_\_\_\_\_\_\_. A. Path Length B. Multiple Scattering Events C. Ionization D. Bragg Peak
Ionization
the process occurs when the antimatter positron combines with the conventional matter electron. In this interaction, the masses of both particles are completely converted into energy. A. Annihilation B. Beta Particle Interaction C. Alpha Particle Interaction D. Neutron Interactions
Annihilation
The energy equivalent of one electron or positron mass is ____.
511 keV
Are uncharged particles. They do not interact with electrons. Do not directly cause excitation or ionization. A. Annihilation B. Beta Particle Interaction C. Alpha Particle Interaction D. Neutron Interactions
Neutron Interactions
Carries a negative charge. A. Corpuscles B. Electrons C. Elastic Interaction D. Characteristic X-rays
Electrons
Thompson termed it as _______ and found out that it is 1,000 times smaller than a hydrogen atom
Corpuscles
True or False
The mass of electron is approximately 1/1836 of that of a proton
True
No energy is transferred from the electron to the sample. Hence, there is no loss of energy. A. Corpuscles B. Electrons C. Elastic Interaction D. Characteristic X-rays
Elastic Interaction
True or False
Elastic scattering happens if the electron is deflected from its path by Coulomb interaction with the positive potential inside the electron cloud.
True
True or False
Inelastic scattering is a general term which refers to any process that causes the primary electron to lose a detectable amount of energy
True
The processes all involve an interaction between the primary beam electrons and orbital electrons of the atom in the sample or material. There is always energy loss. A. Corpuscles B. Inelastic Interaction C. Elastic Interaction D. Characteristic X-rays
Inelastic Interaction
True or False
Incident electron travelling through the atom might transfer part of its energy to an electron located in the atom’s outer most shell
False - inner most shell
True or False
The energy transfer to an inner shell is important because the electronic state of the generated ion is energetically unstable
True
These are emitted when an electron from a higher energy level drops to fill the electron hole in a lower energy level.
Characteristic X-rays
True or False
Every element has a characteristic number of electrons localized in a well-defined energy states
True
True or False
The more electrons and thus energy levels an element has, the more transitions are possible.
True
It requires _____ eV to remove a carbon K electron and ______ eV to remove a tungsten K electron
283 eV
69,508 eV
An alternative to X-ray emission is ejection of an outer electron carrying away the transferred energy of the primary electron as kinetic energy. The process is known as __________.
Auger emission
True or False
Auger electrons are produced when a sample is bombarded with electrons and a characteristic Xray produced by inner shell ionization is reabsorbed, ejecting an electron.
True
True or False
Auger effect is more common in elements with high atomic number because their atomic electrons are more loosely bound and their characteristic X-rays more readily absorbed
False - low atomic number
which loses some of its energy to the inner shell electron
Primary Electrons
which fills the hole in the inner shell
Outer electron
which carries off the surplus energy
Other Outer Electron
True or False
The Braking radiation is the main constituent of the continuous X-ray emission spectrum
True
Several mechanism of inelastic electron matter can lead to the ejection of a _________
secondary electron (SE)
True or False
Electrons located in the valence or conduction band need only the transfer of a small amount of energy to gain the necessary energy to be ejected into the vacuum
True
True or False
Electrons that are located in the inner shells are stronger bound and less readily ejected.
True
