Induced Thermoluminescence

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Induced Thermoluminescence

• Mateo Naranjo

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A brief overview of TL

• What is TL?
• -Its the thermally stimulated emission of
  light from a material
• What are the requirements for TL to happen?
• -The material has to be either an insulator or
  semiconductor (thats why we take off all the
  metallic part of the meteorite first!)
• -Material must have been exposed to radiation
• -It must be stimulated by heating

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So what is the difference between natural and
induced TL?

• Natural TL (Stacys part) is produced by a sample
  in the as received state.
• Induced TL is produced by a sample drained off
  its NTL and subjected to a standard radiation
  dose. The measurement of ITL will provide info on
  the mineralogy and nature of the particles.

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Procedures

• Sample Preparation
• TL (naturalinduced)
• Glow curve analysis
• Data reduction
• Final analysis deductions

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Block diagram for TL measurement apparatus

• Gg

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What parameters are we looking for?

• For ITL, important parameter is TL sensitivity
• Its calculated as the average PH (peak height)
  of sample normalized to the Dhajala meteorite.

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What values did we get?
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• As expected, the TL sensitivity values we
  obtained were consistent with high type 3 / low
  type 4 ordinary chondrites

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Can we compare these values to other parameters?

• Yes! We can compare them to Olivine and Pyroxene
  PMD, a mineralogical measure of the scatter, and
  see if we spot any trends

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Conclusions

• Our TL sensitivity values agreed with high type 3
  / low type 4 ordinary chondrites
• Further comparison with PMD showed a
  proportionallity trend between TL sensitivity and
  pyroxene PMD gt PMD goes down as TL sens. goes
  up
• The olivine PMD shows no relation to TL
  sensitivity (because diffusion is much faster in
  ol)