Radiation Protection

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Radiation Protection

• Protective Devices

start
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Intended Learning Outcome

• That the student will be able to explain the
  rationale behind the use of barriers which act as
  a protection to ionising radiation
• 2

Slide 3
3
Aim of Radiation Protection

• To ensure that radiation doses received by the
  public, patients and staff are as low as
  reasonably achievable
• ALARA principle
• 3

Skip to ALARA slide 8
Slide 4
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Achievable?

• Through a combination of 3 factors
• Distance- use of the Inverse Square Law (ISL)
• Limitation of exposure time
• Use of protective barriers/devices
• 4

Slide 5
5
Protective Devices

• Many manufacturers of lead/ lead equivalence
  products advertise widely. Click here to see the
  product range from a US company called Pacific
  Northwest X-ray Inc.
• 5

Slide 6
6
Why use LEAD (Pb)?

• Lood  
• plomb  
• Blei  
• piombo  
• Chumbo  
• plomo  
• Bly
• Lead is used as a radiation shielding material as
  it has a high atomic number (i.e. 82)
• 6

Slide 7
7
Why use a material with a high atomic number (z)?

• atomic number of an element is the number of
  protons in the nucleus (which is equal to the
  number of electrons around the nucleus)
• for the photoelectric process, the mass
  absorption coefficient increases with the cube of
  the atomic number (z3)
• Revise your knowledge of absorption and
  scattering processes by CONSULTING any good
  quality radiation physics text book
• 7

Slide 8
8
Dose

• Revise your knowledge of radiation doses by
  visiting this next powerpoint produced by the
  University College London urology unit.
• Click here for Radiation Protection this will
  link you to a useful external powerpoint
  presentation which provides a good overview look
  at slides 1 to 11 inclusive
• 8

Slide 9
9
ALARA principle

• As low as reasonably achievable.
• Visit this site which provides a glossary of
  Radiation Protection terms- click here on ALARA
• 9

Continue to slide 10
Go back to slide 3
10
Lead Equivalent

• Lead can be moulded into shapes to form
  protective barriers
• It can also be incorporated into other materials
  such as rubber for use in aprons or gloves or in
  glass for viewing windows. In these cases it is
  the lead atoms present which ( because of their
  high atomic number) are still responsible for the
  majority of the absorption provided for low and
  medium energy (up to 300 kVp) radiation
• 10

Slide 11
11
Lead Equivalence

• Other shielding materials are often compared with
  lead by stating their lead equivalent.
• Lead equivalent of a barrier is that thickness of
  lead affording the same degree of protection
  under specified conditions of irradiation as the
  barrier
• 11

Slide 12
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Personal Protection

• Now revisit the powerpoint produced by University
  College London nephrology unit and look at
  slides 12 to the end.
• Click here
• 12

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Self Assessment Quiz

• See if you can answer the following questions
• Multiple Choice quiz

Crossword next
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crossword

• Try this next quiz which is in the form of a
  crossword

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HENRE

• SUBGROUP 2 2005