Interaction With matter

Question 1

Interaction of radiation with matter

Answer 1

Particle interaction

Photons and gamma ray interaction

Question 2

Charged particle lose energy by interacting with orbital electrons

Answer 2

Excitation and ionization

Question 3

Transfer of energy to electrons

Answer 3

Excitation

Question 4

Also known as de- excitation process

Answer 4

Auger effect

Question 5

The electron makes a transition to vacancy

Answer 5

Auger electron

Question 6

Ejection of an electronresulting to ion pair

Answer 6

Ionization

Question 7

Electrons posses sufficient energy to produce further ionizations

Answer 7

Secondary ionization / delta rays

Question 8

_____ of energy deposits on soft tissue in soft tissue occurs via ionization

Answer 8

70%

Question 9

As electron energy ______ , the energy loss via excitation ______

Answer 9

Decreases

Increases

Question 10

Average number of primary and secondary ion pairs

Answer 10

Specific ionization

Question 11

Specific ionization is expressed in

Answer 11

Ion pairs per millimeter (IP /mm)

Question 12

Spcific ionization increases with

Answer 12

Square of the electrical charge ( Q) of the particle

Question 13

As coulombic field ______ , the incident particle velocity _____

Answer 13

Increases

Decreases

Question 14

Kinetic energy of alpha particles by natural occuring radionuclides extend from

Answer 14

4.05 MeV /in 2.49 air ( Th -232) - 10.53 MeV/ 11.6 cm ( Po -212)

Question 15

Specific ionization on air

Answer 15

7000 lp/mm

Question 16

Specific ionization on soft tissue

Answer 16

10 million lp/mm

Question 17

Alpha particle slows down , specific ionization increases to the maximum

Maximum alpha ray

Answer 17

Bragg peak

Question 18

Paths of heavy charged particles in matter

Answer 18

Charged particle tracks

Question 19

Distance travelled by a particle

Answer 19

Path length

Question 20

Depth of penetration of the particle in matter

Answer 20

Range

Question 21

Electrons follow a _________ as a result in multiple scattering caused by coulmbic deflection

Answer 21

Tortuous path

Question 22

Coulombic deflection

Answer 22

Repulsion/ attraction

Question 23

Heavy charged particle results in dense and

Answer 23

Linear ionization track

Question 24

Measure of the average amount of energy deposited locally

Answer 24

Linear Energy Transfer

Question 25

LET is often expreesed in units

Answer 25

keV /mm

eV /mm

Question 26

LET of a charged particle is proportional to

Answer 26

Square of the charge

Question 27

LET of a charged particle is inversely proportional to

Answer 27

Particle’s kinetic energy

Question 28

Produces shorter range and more damaging to the cells

Answer 28

High LET radiation

Question 29

Higsr range in matter and less damaging

Answer 29

Low LET radiation

Question 30

Interaction that deflects a particle or photon from its trajectory

Answer 30

Scattering

Question 31

Total kinetic energy of the colliding particle is unchanged

Answer 31

Elastic scattering

Question 32

Occurs wit a loss of kinetic energy or change in energy

Answer 32

Inelastic

Question 33

Electrons undergoing inelastic interaction emits electromagnetic radiation

Answer 33

Radiative interaction

Question 34

RadiTion emission accompanying electron deceleration

Answer 34

Bremsstrahlung radiation

Question 35

Bresstrahlung is a german word meaning

Answer 35

Breaking radiation

Question 36

When a positron reaches the end of its range

Answer 36

Positron annihilation

Question 37

Positron annihilation forms 2 opposite directed _______ photons

Answer 37

0.511 MeV

Question 38

It cannot cause excitation or ionization but interacts with the nuclei

Answer 38

Neutron Interaction

Question 39

Neutron interaction is like ________ producing recoil niclei that lose energy

Answer 39

“Billiard ball scatter