Here is a link to my GitHub account where I have depository with my final code and a pdf that explains my code in good detail and another that goes into the details of the development of the code. Also it has plots for what you would expect for running my code for a simple case. Good luck!
https://github.com/mannion9/NeutronDistanceSimulation
Also here is a link to some tutorials I wrote as I was working over the past year or two.
https://github.com/mannion9/Intro-to-Python