INTERACTION OF PARTICULATE RADIATION WITH MATTER

Question 1

Particles of ionizing radiation include charged
particles, such as — particles, ——,
——-, ——— particles, and ——, and
uncharged particles, such as —–.

Answer 1

alpha particles, protons,
electrons, beta particles, and positrons, and
uncharged particles, such as neutrons

Question 2

—– charged particles all interact with
matter by electrical forces and lose kinetic
energy via —–, ——-, and
———

Answer 2

energetic, excitation, ionization radiative losses

Question 3

———– and ——– occur when charged
particles lose energy by interacting with
orbital electrons.

Answer 3

Excitation, ionization

Question 4

Is the transfer of some of the incident
particle’s energy to electrons in the
absorbing material, promoting them to
electron orbitals farther from the nucleus
(i.e., higher energy levels).

Answer 4

Excitation

Question 5

The energy transferred to an electron does
—– its binding energy.

Answer 5

does
not exceed

Question 6

The electron will return to a lower energy
level, with the emission of the excitation
energy in the form of ————-

Answer 6

electromagnetic
radiation or Auger electrons

Question 7

If the transferred energy exceeds the binding
energy of the electron whereby the electrons
is totally ejected from the atom.

Answer 7

Ionization

Question 8

The result of ionization is an ——–
consisting of the ejected electron and the
positively charged atom

Answer 8

ion pair

Question 9

Result from the ejected electrons that have
sufficient energy to produce further
ionizations.

Answer 9

Secondary Ionization

Question 10

in Secondary Ionization
, the electrons are called? These electrons are called ——–

Answer 10

delta rays.

Question 11

The number of primary and secondary ion
pairs produced per unit length of the charged
particle’s path is expressed in ——-

Answer 11

ion pairs
(IP)/mm.

Question 12

Specific ionization —— with the
increases of the particle and
decreases with incident ——.

Answer 12

electrical charge, particle velocity

Question 13

A ——- produces a greater
coulombic field; as the particle loses energy,
it slows down, allowing the coulombic field to
interact at a given location for a longer period
of time.

Answer 13

larger charge

Question 14

An alpha particle can have as high as —–

Answer 14

7,000
IP/mm in air.

Question 15

As the alpha particle slows, the specific
ionization increases to a maximum (called
the ???????).

Answer 15

bragg peak

Question 16

As the alpha particle decreases rapidly,
alpha particle ??????? and
becomes electrically neutral, thus losing its
capacity for further ionization

Answer 16

picks up electrons

Question 17

_______ follow tortuous paths in matter as
the result of multiple scattering events
caused by coulombic deflections (repulsion
and/or attraction).

Answer 17

electrons

Question 18

_______ has a larger mass results in a
dense and usually linear ionization track

Answer 18

alpha particle

Question 19

——– of a particle is defined as the
actual distance the particle travels

Answer 19

Path length

Question 20

_______ is defined as the actual
depth of penetration of the particle in matter

Answer 20

Range of a particle

Question 21

The path length of the electron almost
always __________

Answer 21

exceeds its range

Question 22

The path length and range of the alpha
particle is being nearly ——–

Answer 22

equal

Question 23

The amount of energy deposited per unit
path length.

Answer 23

LET

Question 24

LET is usually expressed in units of
______

Answer 24

eV/cm

Question 25

LET of a charged particle is proportional to the _________ and inversely proportional to the _________

Answer 25

square of the charge, particle’s kinetic energy

Question 26

is the product of specific ionization (IP/cm) and the average energy deposited per ion pair (eV/IP)

Answer 26

LET