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Flashcards in Radiation Monitoring Deck (61)
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1
Q

Worker who occasionally works in a controlled area and may receive significant occupational exposure needs to be

A

Monitored indivudually

2
Q

Personnel Monitoring Devices

A

FPOT

Film badge dosimeter
Pocket dosimeter
Optically stimulated luminescence
Thermoluminescent dosimeter

3
Q

Purpose of personnel monitoring devices are

A

ICA

Identifies high dose
Control of radiation exposure
Assessment if working places

4
Q

Commonly used to measure and record radiation exposure sue to gamma rays, X-rays and beta particles

A

Film badge dosimeter

5
Q

The film in film badge dosimeter

A

Packed in a light proof, vapor proof envelope preventing light, moisture or chemical vapors from affecting the film

6
Q

Film is coated with

A

Two emulsion

7
Q

Emulsions in FBD

A
  1. Large grain, fast emulsion that is sensitive to low levels of exposure
  2. Fine grain, slow emulsion that is less sensitive to exposure
8
Q

Causes of inaccuracy of FBD

A

EDEH

Effect of dosage on the film but not received by the wearer
Effect of hear on film

9
Q

Advantages of FBD

A

ACAP

Accurate for exposures greater than 100mrem
Can measure doses due to different types of radiation
Able to distinguish diff energies of photons
Provides permanent record

10
Q

Worn between the neck and the waist

A

Whole body badges

11
Q

Worn on a finger of the hand most likely to be exposed too ionizing radiation

A

Ring badges

12
Q

It is worn for a period of tine (3 months pr less)

A

Thermoluminescence Dosimeter (TLD)

13
Q

TLD is a phosphor such as

A

Lithium Fluoride

calcium Fluoride

14
Q

TLD’s can measure doses as low as

A

1 mrem

15
Q

Advantages of TLD

A

RRLS

Reusable
Relative energy independence
Linearity of response to dose
Sensitive to low doses

16
Q

Disadvantage of TLD

A

No permanent record

17
Q

It means emitting light when heated

A

Thermoluminiscent

18
Q

It is a process in which a pre-irradiated material when subjected to an appropriate optical stimulation, emits light signal proportional to the absorbed dose

A

Optically Stimulated Luminescence

19
Q

Stimulation is carried out

A

Optically rather than thermally

20
Q

OSL emission is highly influenced by

A

Energy

Intensity of the stimulating optical beam

21
Q

It is the simplest and the most straight forward OSL process in which a pre-irradiated material is stimulated by a light source of constant intensity

A

Continuous wave optically stimulated luminescence

22
Q

A process in which the optically stimulated luminescence signal from a pre-irradiated material is measured after a stimulation light is switched off

A

Delayed optically stimulated luminescence

23
Q

A form of DOSL in which the luminescence is recorded intermittently following a stimulation by very short pulses with a frequency of about thousands of hertz

A

Pulsed optically stimulated luminescence

24
Q

These are used to provide the wearer with an immediate reading of his or her exposure to x-rays and gamma rays

A

Pocket dosimeter

25
Q

They are commonly worn in the pocket

A

Pocket dosimeter

26
Q

Two types of pocket dosimeter

A

DD

Direct read pocket dosimeter
Digital electronic doaimeter

27
Q

The dosimeter contains a small ionization chamber with a volume of approximately two millemeters

A

Direct read pocket dosimeter

28
Q

The electrons produced by ionization are attracted to, and collected by

A

Positively charged central anode

29
Q

The amount of movement is ________________ to the amount of ionization which occurs

A

Directly proportional

30
Q

It is viewed on a translucent scale which is graduated in units of exposure

A

Fiber

31
Q

Advantages of DRPD

A

Immediate reading

Reusable

32
Q

Disadvantages of DRPD

A

Limited range
Inability to provide a permanent record
Reading loss due to dropping

33
Q

These dosimeters record dose information and dose rate

A

Digital electronic dosimeter

34
Q

DED most often use

A

Geiger Müller counters

35
Q

Digital electronic dosimeter includes what feature which emits an audible signal or chirp with each recorded increment of exposure

A

Audible alarm

36
Q

Types of workplace/ area monitoring

A

PIGS

Proportional counters
Ionization chambers
GM tubes
Scintillation detectors

37
Q

The choice of monitoring instrument depends on

A

PHER

Photons or particles
High or low levels
Energy of photons
Required accuracy

38
Q

Contamination detectors for Beta emitters

A

GM tube

Proportional counter

39
Q

It is the simplest of all gas-filled radiation detectors, and is widely used for the detection and measurement of certain types of ionizing radiation, x-rays and gamma rays and beta particles

A

Ionization Chamber

40
Q

The essential component of ionization chamber are the

A

Anode and cathode

41
Q

The potential difference between the anode and cathode

A

100-500 volt range

42
Q

The most commonly used for quantifying alpha and beta activity, they are also used for neutron detection

A

Proportional counters

43
Q

The pulses produced by a proportional counter are larger that those produced by

A

Ionization chamber

44
Q

In proportional counters it usually serves as the cathode

A

Cylinder

45
Q

In a proportional counters the anode is made up of

A

Fine metal wire stretched along the axis of the cylinder

46
Q

It occurs near the anode at a distance comparable to the wire’s diameter

A

Gas amolification

47
Q

Proportional counter are filled with

A

Inert gas

48
Q

It is an instrument used for measuring ionizing radiation such as alpha particles, beta particles and gamma rays using ionization effect produced in a Geiger-Müller tube

A

Geiger counter

49
Q

Used to detect presence of low-level radioactive particles and rays

A

Geiger counter

50
Q

The Gm tube is filled with an inert gas such as

A

Helium
Argon
Neon

51
Q

The most important resource a radiographer has

A

Survey meters

52
Q

To determine

A

The presence and intensity of radiation

53
Q

Are portable radiation detection and measurement instruments used to check personnel, equipment and facilities for radioactive contaminatin

A

Survey meters

54
Q

To measure external or ambient ionizing fields

A

Survey meters

55
Q

One of the oldest type of radiation detector bc measurements could be made with photographic film

A

Scintillation detectors

56
Q

A material that exhibits scintillation when exposed bu ionizing radiation

A

Scintillator

57
Q

Types of inorganic scintillators

A

Cesium iodide with thalium
Cesium iodide with sodium
Sodium iodide with thanlium

58
Q

The most common type of material is a type of salt called

A

Sodium-iodide

59
Q

The light produced from the scintillation process is reflected through a clear window where it interacts with device called

A

Photomultiplier tube

60
Q

To minimize contamination risks

A

Use protective gloves and clothing
Adopt clean operating conditions
Adopt good laboratory practice

61
Q

Types of monitoring

A

PA

Personnel monitoring
Area/Workplace monitoring