EXSAN

User’s Guide

Clone EXSAN:

git clone https://github.com/lanl/EXSAN.git

Link NJOY2016 executable to EXSAN/working subdirectory:

cd EXSAN/working

ln -s ../../../NJOY2016/bin/njoy njoy

​

Note: the ../../../NJOY2016 should be changed to the path where NJOY2016 is installed on your system!

Launch EXSAN from within the /EXSAN directory:

cd EXSAN

python exsan.py

Select ENDF/B-VIII.0

Click Download Now

Be patient...download may take a while….

Select ENDF/B-VIII.0

​

Enter desired Doppler broadening temperature (Default 300K)

​

Select the multigroup energy bin structure (default 30 group)

​

Click Process with NJOY

Be patient...NJOY processing may take a while….

After NJOY processing is complete, Select the ENDF/B-VIII.0 library

​

Select an element,

then an isotope,

then a reaction.

​

Then, click the Plot button

​

Now, click the Multigroup tab, and add the same element, isotope, and reaction

​

Click the Cursor checkbox,

Then, click the Plot button

​

Click Clear All to clear all plots

Click Pointwise, and select an isotope for plotting all reactions, and click Plot

Use navigation buttons to pan, zoom, or save the

image

Which isotope has the largest (n,alpha) cross section at 0.5 MeV?

​

Enter 5e5 in the additional energy text entry

​

Select (z,alpha) for comparison

​

Click Analyze All

​

​

Which isotope has the largest (n,alpha) cross section at 0.5 MeV?

​

Click the Sort by x-sec

and E_User radio buttons

​

Scroll to the bottom of the left

text area to find the answer.

​

What about at thermal?

Click the Th radio button and scroll to the bottom.

​

Plot the elastic scattering cross sections for H₂O and D₂O

​

​

On the Multigroup tab, select the elastic scattering reaction, then click Analyze All

​

​

​

Plot the elastic scattering cross sections for H₂O and D₂O

​

Select the Mix tab, and using the pull-down menus and text entry fields, construct (H-1)₂(O-16).

​

Click the Plot mix button

​

​

Plot the elastic scattering cross sections for H₂O and D₂O

​

Select the Mix tab, and using the pull down menus, and text entry fields, construct (H-1)₂(O-16).

​

Click the Plot mix button

​

​

Plot the elastic scattering cross sections for H₂O and D₂O

​

Now, construct (H-2)₂(O-16).

​

Click the Plot mix button

​

Type the keyboard shortcut P to plot the cross sections

​

​