Difference between revisions of "LB Thesis NewSNR Corrections"

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[[File:Se81m SpecificActivityRatiovsConcentration SegebadeNormalized.png|200px]]
 
[[File:Se81m SpecificActivityRatiovsConcentration SegebadeNormalized.png|200px]]
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If I apply Dr. Forest's suggested decay correction as were applied to the ratios before (multiply by <math> 1-e^{-\lambda_{el} t_i} </math>, I get
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[[File:Se81m SpecificActivityRatiovsConcentration SegebadeNormalized TFDecayCorrected.png|200px]]
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This still doesn't make physical sense. Try multiplying by the mass of the sample to see a change.
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[[File:Se81m SpecificActivityRatiovsConcentration SegebadeNormalized TFDecayCorrected MassMultiply.png|200px]]

Revision as of 16:22, 25 July 2018

First plot the efficiency corrected activity as a function of concentration. These points are not weighted by mass, but they are fully corrected as per the thesis otherwise. These values are the activity at the highest value of N/B

HighSNR AvsConc Se81m.png

This plot doesn't look very good as the 50% sample has a lower activity than the 10% sample. Try plotting this at the time of beam off. Note these are done using fits with the accepted half life vs. the experimental half life. The error bars represent |(Free Fit A) - (Fixed Fit A)|

Se81m AvsConc BeamOff.png

Perhaps the difference comes from the fact that the irradiation times were different, but to normalize to a standard beam time, a reference material must be used. Segebade says "Since, as already mentioned, yield values are normalized for a common exposure period of one hour, the following expression is required, which converts the individual activities yielded using other irradiation times to those after standard exposure period T (1h):

[math] N(T) = \frac{A_{0,el}}{A_{0,Ni}} \times \frac{(1-e^{-\lambda_{el}T})}{(1-e^{- \lambda_{el} T_i})} \times \frac{(1-e^{- \lambda_{Ni} T_i})}{(1-e^{-\lambda_{Ni} T})} [/math]

Where [math] T_i [/math] is the actual exposure period and T is the normalized exposure period of 1 hour"

So lets try to correct these ratios using Nickel

For correcting the 50%, we have (note these are the fixed fit values)

[math] N(T) = 0.62 \times \frac{0.52}{0.32} \times \frac{0.01}{0.02} = 0.50 [/math]

This ratio is lower than its original value (0.62), which makes sense because the nickel would not die off as much in the beam. The 10% and 1% values should not need this correction as they were irradiated for an hour, so the correction goes to unity. Plot the ratio of the specific activity as a function of concentration.

Se81m SpecificActivityRatiovsConcentration SegebadeNormalized.png

If I apply Dr. Forest's suggested decay correction as were applied to the ratios before (multiply by [math] 1-e^{-\lambda_{el} t_i} [/math], I get

Se81m SpecificActivityRatiovsConcentration SegebadeNormalized TFDecayCorrected.png

This still doesn't make physical sense. Try multiplying by the mass of the sample to see a change.

Se81m SpecificActivityRatiovsConcentration SegebadeNormalized TFDecayCorrected MassMultiply.png