Plotting Reaction Rate vs Temperature with MATLAB

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SUMMARY

This discussion focuses on plotting reaction rates as a function of temperature using MATLAB, specifically for fusion cross section data obtained from the EXFOR website. The user seeks to perform numerical integration with sigma and E values, emphasizing the need for a table of cross section values rather than a plot. It is confirmed that the cross sections are evaluated at energy E, and the flux may vary with E. The integration process involves evaluating E multiplied by the exponential function.

PREREQUISITES
  • Understanding of MATLAB for numerical integration
  • Familiarity with fusion cross section data and its sources, such as EXFOR
  • Knowledge of Maxwellian conditions in plasma physics
  • Basic concepts of differential cross sections and their evaluation
NEXT STEPS
  • Learn MATLAB's numerical integration functions, such as integral and trapz
  • Research Maxwellian distribution and its application in nuclear physics
  • Study the differences between cross sections and reaction rates in nuclear reactions
  • Explore how to extract raw data from graphical plots on the EXFOR website
USEFUL FOR

Researchers in nuclear physics, MATLAB users involved in numerical analysis, and anyone interested in plotting reaction rates from cross section data.

Rhony
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I know how to get fusion cross section plots from the exfor website but now I need to plot the reaction rate as a function of temperature. According to the image, I have sigma and E values as x and y data. How do I integrate using matlab .
I know how to get fusion cross section plots from the exfor website but now I need to plot the reaction rate as a function of temperature. According to the image, I have sigma and E values as x and y data. How do I integrate using MATLAB .
 

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It would seem this is a MATLAB numerical integration problem.

So one has a nuclear (nuclei) energy spectrum, and I assume T is the average temperature (related to <E>) of the nuclei in the plasma. Is this correct?
 
Yes that's correct. I had got pb11 cross section data points from exfor. Now using maxwellian conditions, I wanted to use those to plot reaction rate. Its done in many textbooks where the explain the difference between cross section and reaction rate, but they never mention the steps followed.
 
Do you have a plot of the cross sections, or a table of the cross section values? You will need the table of values.
If you only have the plot, check the website again to see if there is a way to download the raw data.

Next, check to see if the cross sections are evaluated at "E", are are they differential cross sections as a function of E? (sigma(E)). I've seen it both ways.
If they are not differential cross sections, you will need to divide the cross section by the appropriate "delta-E" to put it in differential form.

Now you have:
  • Values of sigma(E)
  • T is a constant value
  • You can evaluate E*exp()
It is just a matter of performing the numerical integration.
 
rpp said:
Do you have a plot of the cross sections, or a table of the cross section values? You will need the table of values.
If you only have the plot, check the website again to see if there is a way to download the raw data.

Next, check to see if the cross sections are evaluated at "E", are are they differential cross sections as a function of E? (sigma(E)). I've seen it both ways.
If they are not differential cross sections, you will need to divide the cross section by the appropriate "delta-E" to put it in differential form.

Now you have:
  • Values of sigma(E)
  • T is a constant value
  • You can evaluate E*exp()
It is just a matter of performing the numerical integration.
I just realized my last post was incorrect, and I don't see a way to edit it. The cross sections are always going to be evaluated at "E", you should never have to divide by "delta-E". It is the flux that can be a function of E. Sorry for the confusion.

Mentors: is there a way to edit my previous post?
 

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