Difference between revisions of "Cf-252 FTC-CFZ-431"

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4.2 <math>\mu g</math> would generate <math>9.67 \times 10^{6}</math> neutrons per second. The discrepancy between these two numbers gives a 2% error.  
 
4.2 <math>\mu g</math> would generate <math>9.67 \times 10^{6}</math> neutrons per second. The discrepancy between these two numbers gives a 2% error.  
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=initial source composition=
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=Initial source composition=
 
CF252 used in the US is produced in batches at Oak Ridge National Laboratory which all have similar isotopic make up. I found the isotopic composition of a batch produced in 1991, two years before the production date of our source<ref> http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-12-22883 </ref>. Assuming our source has the same isotopic composition as the 1991 batch and a total mass of 4.2 <math>\mu</math>g, the values in the following table can be calculated.
 
CF252 used in the US is produced in batches at Oak Ridge National Laboratory which all have similar isotopic make up. I found the isotopic composition of a batch produced in 1991, two years before the production date of our source<ref> http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-12-22883 </ref>. Assuming our source has the same isotopic composition as the 1991 batch and a total mass of 4.2 <math>\mu</math>g, the values in the following table can be calculated.
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{| border="2"
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!rowspan="2"| nuclide !! rowspan="2"| Atom % !! rowspan="2"|NAtoms in 1993 <math>\times 10^{15}</math> !! rowspan="2"|<math>T_{1/2}</math> [y] !! colspan="2" | decays <math>[s^{-1}]</math>
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|-
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!<math>\alpha</math>!! SF
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! <math>^{249}Cf</math>
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| 3.41 || - || 351
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|-
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|}
  
 
=Table of rates=
 
=Table of rates=

Revision as of 20:44, 19 January 2017

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Overview

An official document for the CF-252 source with serial number FTC-CFZ-431 provides a value for the neutron rate and CF-252 mass as of 03/19/1993.

The initial neutron rate and mass of cf-252 are stated to be 107s−1 and 4.2μg, respectively.

4.2 μg would generate 9.67×106 neutrons per second. The discrepancy between these two numbers gives a 2% error.

Initial source composition

CF252 used in the US is produced in batches at Oak Ridge National Laboratory which all have similar isotopic make up. I found the isotopic composition of a batch produced in 1991, two years before the production date of our source<ref> http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-12-22883 </ref>. Assuming our source has the same isotopic composition as the 1991 batch and a total mass of 4.2 μg, the values in the following table can be calculated.


nuclide Atom % NAtoms in 1993 ×1015 T1/2 [y] decays [s−1]
α SF
249Cf 3.41 - 351

Table of rates

Click here to open a table giving neutron rates and C-252 activity from dates 1/2017 to 12/2029. This calculation only includes neutrons from Cf-252, since all other daughter nuclei and possible impurities have a very low SF rate compared to Cf-252.

Formulas

Formula used for neutron rate [s−1]:

k=(0.5)(year−1993)+month−3122.645

n0rate=9.835×106×k

and for Cf-252 activity [μCi]:

activity=2283.3×k

References

<references/>


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