Tuesday, June 10, 2014

Lecture 3: Decay Kinetics

This lecture covers the fundamental equations that describe the decay of radionuclides; covered in two parts. Basic equations and their utility are presented. The implications on error from counting is provided. Equations for mixtures, equilibrium, and branching of radionuclides are covered. The use of a program to solve the Bateman equation is presented.  The program is ERC Nuclide. The use of cross sections in determining production rates are covered. Saturation in isotope production due to the decay of the daughter is described. Discussion of natural radiation and dating are given. Examples are provided using the equations under a host of conditions. These include examples for dating from 238U, 14C, and the Oklo reactor. 

23 comments:

  1. I read the lecture one and the current hard copy readings. My intention is to bring in quiz one on Friday

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  2. Regarding lecture 3, I am surprised and relieved at the similitudes to standard chemical reaction dynamics. Yes It is more complex yet the terms are recognizable and my head is not yet exploding.

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    1. Relating the topic to chemistry is an excellent approach and one that works. Happy to hear your head is together.

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  3. Decay Kinetics is a very intriguing subject, and I found the topics of Production Rates and Saturation of Isotopes to be rather useful and could be very applicable in this field.
    Is the ERC Nuclide program available for OSX? (I was unable to install it on my mac)

    - Chris

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    1. We will use the saturation term in equilibrium examples on Friday. The ERC program is not available for the mac, sorry.

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    2. I'm having the same issue on my tablet hybrid. It might have to deal with this http://www.ergoffice.com/downloads.aspx?Type=software

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  4. I finished the lecture. Cool stuff about decay kinetics. I'm also having problems getting the ERC Nuclide program to work on my computer. I have a PC

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  5. Sorry to hear about the program. try the link "ERG Nuclides 2.0.0.2 download from ERG" on the lecture webpage. This link is (http://www.ergoffice.com/Download%20Files/NToolsV2002.zip). Let me know if you get it to go.

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  6. Kinetics applied to radioactive isotope decay is so fascinating.

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  7. I liked these videos. They both reinforced and expanded my prior knowledge of nuclear decay.

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  8. Does anyone know how to determine branching ratios? Like for Bi212 the alpha branch is 36% and the beta branch is 64%. Where is that from? I couldn't find it from the chart of nuclides or the table of isotopes.

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    1. Michael, in the Table of Isotopes the Branching Ratios are listed. For Bi212 (Page 9131) It lists them directly below the green text.

      Here is the one for Bi212 -
      Levels and g-ray branchings:
      0, 1(-), 60.556 m, [AB ], %b-=64.066,
      %a=35.946, %b-a=0.023

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  9. one can also find the data from the BNL site (http://www.nndc.bnl.gov/chart/chartNuc.jsp). Look up 212Bi and use the ground state.
    The table of the isotopes (TOI) is also available online and has the 212Bi data (http://ie.lbl.gov/toi/nuclide.asp?iZA=830212)

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  10. The lectures on decay kinetics were interesting. I enjoyed all of the applied math, although I had some trouble making it through a couple steps in the derivation of the equation describing how the amount of daughter isotope relates to the initial amount and the growth of the daughter from the parent isotope.

    The applications for dating are really cool. I had previously learned a little about carbon-14 dating, but did not know that uranium-238 was used primarily for time scales on the billions of years.

    -Zach

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    1. thanks for the comments. We will have more examples of dating on Friday.

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  11. Great lecture overall. There was an example that had me stumped though, on the nuclei production example in the second video (in which we're calculating rate formation of Fe-59 from Fe-58), in one of the very first steps, the number of atoms of Fe-58 is calculated. This equation is multiplied by a factor of 0.0028, which is identified as the percentage of iron that is Fe-58. I was wondering where this came from and where we may find a reliable source for these values should we be given a problem like this one on a quiz or exam.

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    1. It's a decimal representation of the %abundance of Fe-58, which is 0.28%. You can find that value here:

      http://www.nndc.bnl.gov/wallet/zz11/z026.html

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  12. Finished viewing lecture 3. Like phillip mentioned in a previous comment, I found the decay kinetics to be very similar to reactions kinetics seen in physical chemistry courses. I did not entirely understand what the saturation rate was describing in the formation of products.

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  13. We will discuss saturation on Monday 16 June

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