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Isotope halflife table by progamming

  1. May 15, 2014 #1
    i wan to do the folowimg :
    [ 1 ] use the computer to find halftimes of isotoops that are jet unkown
    [ 2 ] i want to use genetic programming
    [ 3 ] i use the idea that there is a function = halftime( protons , neutrons )

    i have questions :
    - is [ 1 ][ 2 ] a good idea
    - i dont know if this [ 3 ] is right
    - i need a halftime of isotoops tabel in sec . where can i find this

    remark :
    - [ 2 ] is being writen [ by me ] in :
    - - liberty & just basic [ ready but no IO jet ]
    - - free basic [ no proof of concept jet ]
    - - C++ [ no proof of concept jet ]
    - - python 2.7 [ proof of concept ]
  2. jcsd
  3. May 15, 2014 #2


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    Staff: Mentor

    I'm no nuclear physicist, but I would be extremely surprised if there was a simple function linking the number of nucleons with the lifetime of an isotope.

    As for using a genetic algorithm, what would be your search space?
  4. May 15, 2014 #3
    Is there any theory linking half-life with number of protons and neutrons? Or is it all just derived from experiment?
  5. May 15, 2014 #4


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    Science Advisor

    There are theories, but the actual data is from experiment.
  6. May 26, 2014 #5
    @ drclaude :
    i think it is not a simple function :
    - halftime( protons , neutrons )
    but GP can find complex ones to

    GP wil never find a exact one
    but a nice near one can be useful

    i wil use every operator i can think of

    where can i find a tabel in sec. for this ?

    remark :
    - c++ code : stil a error
    - liberty & just basic code : complete only file IO missing
    - python code : complete only file IO missing
    - freebasic code : lots of errors
  7. May 26, 2014 #6


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    Staff: Mentor

  8. Jul 24, 2014 #7
    i have now a random acces file whit the known halftimes

    somtimes the file remarks ´stable´ in the halftime field
    the halftimeinsec field is then ´0.00e00´

    what must i take as halftimeinsec if halftime = ´stable´

    the array halftime( protons , neutrons ) is not complete

    what do i use as halftime(p,n) if halftimeinsec is unkown
    i cant use 0 becoause i want to do
    erroronthispoint = abs( output ~ halftime(p,n) ) div halftime(p,n)
    i want the relative error
  9. Jul 24, 2014 #8


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    Gold Member
    2017 Award

    Just use a very large number for halftimeinsec. Any (correct) formula that includes decay will just ignore the decay for a stable isotope in its result. That's what you want, isn't it?
  10. Jul 24, 2014 #9
    so for 'stable' i can use '9.99e99' sec

    but what do i use for the missing ones ?

    i cant use 0
  11. Jul 24, 2014 #10


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    Science Advisor
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    2017 Award

    You have to do more searching or assume they are stable. Otoh, there are plenty ways of labelling data so that your program can pick it up and notify the user. If you don't have the information then you can't use it.
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