Lecture 1

Question 1

Radiation was discovered in ?

Answer 1

1985
Which was working with cathode ray tube
the room was dark , He tried to block the emissions by covering the tube first by a piece of cardboard and then by a piece of wood but the phosphorus still glowed
The X-light easily penetrated cardboard, books, wood and cloth

Question 2

When properties of his x rays discovered ?

Answer 2

By the end of the year 1895 , which they traveled in a straight line from the point that the cathode rays in the tube struck the glass wall of the tube
and they were exponentially absorbed by matter

Question 3

What is radiation ?

Answer 3

Form of energy
It is a general process of emitting radiant energy in form of waves or particles

and emitted in the decay process of unstable nuclei or by excitation of atoms

Question 4

Is the process of removing one or more electrons from atoms by incident photon is ?

Answer 4

Ionization

Question 5

Types of radiation ?

Answer 5

Ionizing and non ionizing radiation

Radiation that has sufficient energy to dislodge orbital electrons
Examples of ionizing radiation: alpha , beta particles

Radiation that has not sufficient energy to dislodge orbital electrons
Examples of non-ionizing radiation: microwaves

Question 6

What are Radioactive particles?

Answer 6

Alpha and beta

Question 7

Electromagnetic waves ?

Answer 7

x ray and gamma

Question 8

Alpha ?

Answer 8

Best description: is helium nuclei
Large particles and slow in movement.
Very short penetration
a few cm in air (4-8 cm)

It can Protected with standard Personal Protective Equipment (PPE):
Low penetration (Paper & cloth adequate barriers)

Travel distance - centimeters (Heavy particles)

Hazards: Ingestion or inhalation
Deposits in organs (kidneys, liver, lungs, bone)
Immediate damage

Question 9

Beta ?

Answer 9

An electron emitted from nucleus of radioactive atom
Produce by pair production or in nuclear disintegration

High speed electron
More penetrating than alpha

Special PPE required:
Travel distance 10 to 15 feet (lighter weight)
Penetrates skin (metals, plastic, glass barriers)
Hazards: Contact, inhalation, ingestion

Question 10

Electromagnetic spectrum ?

Answer 10

Form of energy
and Consists of simultaneous electric and magnetic wave

Question 11

Properties of electromagnetic wave ?

Answer 11

As frequency (f) increases, energy (E) increases
Demonstrated by the formula: E = hf
As frequency (f) increases, wavelength (λ) decreases
Demonstrated by the formula: c = fλ

Question 12

Xray and Gamma Ray ?

Answer 12

Frequencies- number of wave per second
wavelength- distance between wave
amplitude- height of wave

EM waves travel in space
Travel in same velocity, c= 3X108 m/s
Has no mass, no charge

Question 13

Gamma rays ?

Answer 13

Produce in the nucleus

Standard PPE provides NO PROTECTION
High penetration, travels long distances
Time/Distance/Shielding (concrete, lead barriers)

Hazard: Ionizing penetrating rays
Immediate cellular damage

Question 14

X rays ?

Answer 14

Heterogeneous - many different wave length
Travel in straight lines
it produce scatter radiation

It cause fluoresces , Photographic effect , Ionization effect and Biologic effect

Question 15

Sources of ionizing Radiation ?

Answer 15

Natural environment and man made

Question 16

Cosmic rays , Terrestrial radiation and internal radionuclides ?

Answer 16

Natural Environmental

Question 17

Medical , Industrial , Nuclear power and consumer products ?

Answer 17

Man -made