Chapter 9 Key Terms

Question 1

Activity

Answer 1

describes the quantity of radioactive material; expressed as the number of radioactive atoms that undergo decay per unit time

Question 2

Air kerma

Answer 2

the kinetic energy released per unit of mass air

Question 3

Alpha particle

Answer 3

contains two protons and two neutrons, is equivalent to a helium nucleus, and is emitted from the nuclei of heavy elements as they undergo radioactive decay; it has a great mass and a positive charge

Question 4

Becquerel (Bq)

Answer 4

the SI unit for activity

Question 5

Beta particle

Answer 5

identical to an electron, except it is emitted from the nuclei of radioactive materials; it is very light and negatively charged

Question 6

Compton scattering (Compton effect)

Answer 6

an interaction between x-rays and matter characterized by an incident x-ray photon interacting with a loosely bound outer-shell electron, resulting in removal of the electron from the shell, which then proceeds in a different direction as a scattered photon

Question 7

Curie (Ci)

Answer 7

the unit of activity

Question 8

Dosimeter

Answer 8

a mechanism that can measure amounts of radiation

Question 9

Effective dose

Answer 9

the sum of the weighed equivalent doses for all irradiated tissues and organs; used to measure the radiation and organ-system-specific damage in humans

Question 10

Electromagnetic radiation

Answer 10

a form of energy that is the result of electric and magnetic disturbances in space

Question 11

Field survey instrument

Answer 11

portable device used to measure radiation in a given location

Question 12

Film badge dosimeter

Answer 12

two pieces of film having different sensitivities to x-rays contained within a light, tight envelope; the film emulsion darkens in response to the radiation exposure received

Question 13

Genetic

Answer 13

describes the effects of radiation that appear in the descendants of the individual being irradiated

Question 14

Gray (Gy)

Answer 14

unit of absorbed energy or dose; 1 joule of energy absorbed in each kilogram of absorbing material

Question 15

Integral dose

Answer 15

the total amount of energy imparted to matter; the product of dose and the mass over which the energy is imparted

Question 16

Kerma

Answer 16

kinetic energy released in matter, the energy imparted directly to electrons per unit mass

Question 17

Optically stimulated luminescence (OSL) dosimeter

Answer 17

measures radiation that passes through a thin strip of aluminum oxide; a laser light stimulates the aluminum oxide, which becomes luminescent in proportion to the amount of radiation exposure

Question 18

Particulate radiation

Answer 18

high-energy electrons, neutrons, and protons that produce ionization in matter by direct atomic collisions

Question 19

Personnel monitoring device

Answer 19

instrument worn by health-care workers who work regularly in radiation-exposed environments

Question 20

Photoelectric absorption

Answer 20

an interaction between x-rays and matter characterized by an incident electron with slightly greater energy than the binding energy of the electrons in the inner shells, ejecting an electron from the inner shell while being absorbed in the reaction, resulting in an ionized atom

Question 21

Pocket dosimeter

Answer 21

a personal-use ionization chamber; when exposed to radiation, ionization occurs in the chamber, which neutralizes

Question 22

Quality factor

Answer 22

radiation weighting factor, specific to specific types of radiation; accounts for the biologic effectiveness of the specific radiation

Question 23

Rad

Answer 23

term used to describe the measurement related to the absorbed dose of radiation; unit of absorbed energy or dose applicable to any material; 100 ergs of energy absorbed in 1 gram of absorbing material

Question 24

Rem

Answer 24

term used to describe the measurement of the biologically equivalent dose

Question 25

Roentgen (R)

Answer 25

term used to describe the measurement related to exposure; the unit of exposure in air; the quantity

Question 26

Sievert (Sv)

Answer 26

the product of the absorbed dose in gray and the radiation weighting factor

Question 27

Somatic

Answer 27

describes the effects of radiation that appear in the individual who was irradiated

Question 28

Systeme Internationale d’Unites (SI units)

Answer 28

an international system of units based on the metric system

Question 29

Thermoluminescent dosimeter (TLD)

Answer 29

small chips of thermoluminescent material, usually lithium fluoride; when exposed to radiation, the chips enter a metastable state; when exposed to heat they give off visible light