Other uses of radioactive isotopes

Question 1

What is a radioactive tracer used for?

Answer 1

• follow the path of a substance through a system

Question 2

What is necessary for a tracer to have?

Answer 2

• have a half-life which is stable enough for the necessary measurements to be made and short enough to decay quickly after use
• emit beta or gamma radiation so it can be detected outside the flow path

Question 3

How can the rate of wear of a piston ring ?

Answer 3

• fitting a ring that is radioactive
• as the ring slides along the piston compartment, radioactive atom transfer from the ring to the engine oil
• by measuring the radioactivity of the oil, the mass of of radioactive metal transferred from the ring can be determined and the rate of wear can be calculated

Question 4

How can a radioactive metal ring be made?

Answer 4

• exposing it to neutron radiation in a nuclear reactors
• each nucleus that absorbs a neutron becomes unstable and disintegrates by beta minus emission

Question 5

What else can tracers be used for, besides medical application?

Answer 5

• underground lleaks
• modelling oil resivoirs
• uptake of fertilisers

Question 6

How is metal foil manufactured?

Answer 6

• using rollers to squeeze plate metal on a continuous production line

Question 7

How is a detectors used in foil production?

Answer 7

• measures amount of radiation passing through the foil
• if too thick, the reading drops
• a singal from the detector is fed to a control system to make the roller move closer together to make the foil thinner

Question 8

What type of source is used for thickness monitopring? WHy are other types not uysed?

Answer 8

• beta minus
• long half life
  
  • does not have to regularly be replaced
  • activity does not significantly changeq
• alpha would be absorbed and gamma would pass throuigh without absorbition

Question 9

How can radioactive isotopes be used for power?

Answer 9

• thermally insulated sealed container
  
  • absorbs all radiation
• a thermocouple attached to the container produced electricity as a result of the container becoming warm through radiation
• needs long half life so it does not need to be replaced
  
  • not very long that may requre too much mass to generate the necessary power