Rate Fits
It is also possible to use one of the standard libnucnet rate
expressions to compute the updated rates. These are 1) a single_rate (a single
number for the rate), 2) a rate_table (a table of t9 and rate and, optionally, stellar
enhancement factor), or 3) a non_smoker_fit. As an example of how to do this, we
can use the libnucnet example code create_reac_xml_from_text. Compile the
code as follows:
cd ~/projects/nucnet-tools-code/build/
make -f Makefile.libnucnet create_reac_xml_from_text
cd ../libnucnet/
Now create a text file ../data_pub/dh03.txt for the reaction 4He + 18O →22Ne + γ
with the lines (the data are from the JINA database)
non_smoker_fit
dh03
2
he4
o18
2
ne22
gamma
7
1st resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
-2.926580e+01 -2.069000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
2nd resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
-4.383630e+00 -4.462000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
3rd resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
-3.992690e+00 -5.373000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
4th resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
1.783390e+00 -6.285000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
5th resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
2.544750e+00 -7.119000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
6th resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
3.499400e+00 -7.287000e+00 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -1.500000e+00 0.000000e+00
7th resonance
2 4 8 12 9.66900 0.0 0.0 -1. 0.01 1.9e-06 0
1.268230e+01 -2.180100e+01 0.000000e+00 0.000000e+00
0.000000e+00 0.000000e+00 -5.000000e-01 0.000000e+00
Then create the relevant XML file by typing
./create_reac_xml_from_text ../data_pub/dh03.txt ../data_pub/n15_study/o18_a_g_ne22_fit.xml
The output file ../data_pub/n15_study/o18_a_g_ne22_fit.xml contains these
data for the reaction. You can now edit the file ../data_pub/n15_study_rates.xml
so that the line
<xi:include href="n15_study/o18_a_g_ne22_formula.xml"/>
instead reads
<xi:include href="n15_study/o18_a_g_ne22_fit.xml"/>
When you use n15_study_rates.xml for network calculations, the code will use
the fit instead of the formula to calculate the rate for this reaction. You can modify
or add other reaction rates in this way.
For more details on using libnucnet example codes, please see the blog post available at
http://sourceforge.net/u/mbradle/blog/2012/07/running-libnucnet-examples/.