Chapter 5 Radiation Protection Flashcards

1
Q

An instrument that reads film from badge. It is used to measure the optical density, the intensity of light transmitted through a given area of the dosimetry film, and compares it with the intensity of light incident on the anterior side of film.

A

Densitometer

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2
Q

Sent by monitoring company– serves as a basis for comparison with the remaining film badges after they have been returned to the monitoring company for processing

A

Control Badge

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3
Q

What does a film badge record?

A

Whole body radiation exposures accumulated at a low rate over a long period of time

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4
Q

What are the 3 parts of the film badge?

A
  • durable lightweight plastic film holder
  • assortment of metal filters
  • film packet
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5
Q

Sensitivity range of the film badge?

A

0.1 mSv (10 rem) to as high as 5000 mSv (500 rem)

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6
Q

What is the main advantage of the film badge?

A

It’s cheap

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7
Q

What type of radiation does the film badge monitor?

A

low energy x-radiation, gamma radiation, and beta radiation

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8
Q

What is the disadvantage of the film badge?

A

Temperature and humidity extremes can cause fogging

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9
Q

What is the most common type of personnel monitoring device that replaced the film badge?

A

Optically Stimulated Luminescence (OSL)

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10
Q

What type of detector is used in OSL?

A

aluminum oxide

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11
Q

How is an OSL read out?

A

Laser light at selected frequencies

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12
Q

What are the three types of filters used in an OSL?

A
  • Aluminum
  • Tin
  • Copper
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13
Q

What’s the sensitivity range for the OSL?

A

1mrem for x-rays and gamma ray photons with energies ranging from 5KeV to greater than 40 MeV

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14
Q

What is the most sensitive type of personnel dosimeter?

A

Pocket Ionization Chamber

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15
Q

What do pocket ionization chambers required to have with it?

A

special charging unit

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16
Q

What is the sensitivity range of pocket ionization chambers?

A

0 to 5.2x10^-5 C/kg (0-200mR)

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17
Q

What is the advantage of using a pocket ionization chamber?

A

It provides an immediate exposure read out for worker whos work in high exposure areas

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18
Q

What is the disadvantage of using a pocket ionization chamber?

A

If it is not read each day it may give inaccurate reading because electrical charge tends to escape with time and give false readings and jarring and shock could discharge it

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19
Q

What is contained in the Thermoluminescnt Dosimeter(TLD)

A

Crystalline a form (powder or small chips) of lithium fluoride

20
Q

How is TLD read out?

A

Passing crystals through special heating process

21
Q

What intensity of light is proportional to in TLD?

A

The amount of radiation that has interacted with crystals

22
Q

What’s the advantages of a Themoluminescnt Dosimeter?

A

Over the film badge is that the crystals interact with ionizing radiation as human tissue does making it more accurate

23
Q

What are the disadvantages of using a Thermoluminescnt Dosimeter?

A

The high cost, can only be read once, the readout process destroys the stored information

24
Q

When is personnel exposure monitoring required?

A

Whenever radiation workers are likely to risk receiving 10% or more of the annual occupational EfD limit of 50 mSv (5mrem)

25
Q

What does personnel dosimeter determine?

A

Occupational exposure by detecting and measuring the quantity of ionizing radiation to which the dosimeter has been exposed over a period of time

26
Q

Where is the personnel dosimeter to be worn at?

A

Front of the body at collar level

27
Q

What procedures produce the highest occupational dose?

A

fluoroscopy and special procedures

28
Q

How much more dose the unprotected parts of the head area vs parts under the lead apron

A

10-20xs

29
Q

When is an extremity dosimeter recommended?

A

by imaging professionals performing fluoro procedures that require the hands near the primary x-ray beam

30
Q

Where should an extremity dosimeter be worn at?

A

finger

31
Q

When might you be required to wear2 monitoring devices?

A

during special computed radiography, digital radiography, or conventional radiographic procedures
or if you’re pregnant

32
Q

Where should the 2 monitoring devices be worn at?

A
  • first at collar (primary) outside the lead

- 2nd beneath wrap in the trunk area or at abdomen under the lead

33
Q

What characteristics must personnel dosimeter posses?

A
  • lightweight and easy to carry
  • made of materials durable enough to tolerate normal daily use
  • has to be able to detect both small and large exposure inconsistent timely manner
34
Q

How penetrating radiations and soft scatter radiations will appear different on a film badge

A

Penetrating radiations cast faint shadow on film and soft radiations(scatter) shows more pronounced image

35
Q

On the filter of the film badge how it appears when exposure is from excessive amounts of scatter?

A

fuzzy image from scatter of different angles

36
Q

ON the filter of the film badge how it appears when exposure is from single exposure from primary beam?

A

sharply defined beam

37
Q

Know why a control badge should always have a zero reading

A

It is to be kept in a radiation free area within imaging facility

38
Q

What is included on a personnel monitoring report/

A

Personal data, type of dosimeter, radiation quality, equivalent dose data, cumulative equivalent doses, and inception date

39
Q

What does the letter M signify on a personnel monitoring report?

A

An equivalent dose below the minimum measurable radiation quantity was recorded during that time

40
Q

Who receives and reviews the personnel monitoring reports?

A

Radiation Safety Officer

41
Q

What filter in an OSL absorbs the leas?

A

Aluminum

42
Q

Which filter is an OSL attenuates the most?

A

copper

43
Q

Know which type of pocket ionization chamber is the most common

A

self reading

44
Q

Know where each electrode 9positive and negative) is located on pocket ionization chamber

A
  • positive charged (central electrode)

- negatively charged (outer electrode)

45
Q

What is the function of the material contained within the TLD?

A
  • Sensing material of the TLD

- Radiation causes that LiF crystals to undergo charges in some of their physical properties