Update 10/20/14

Update:

1)  Code is finished product. Made it as general as possible with 6 inputs + cross section fits and resonates data

2) Installed my program to computer and put user manual

3) Looked at resonance widths made much smaller now only fraction get absorbed at high energy

4) Created method to implement scintillator

5) Question for Andrea: In the scintillator are there compounds or are the elements not bound together? What elements are there exactly? Also what distribution of mean free paths should I use? Gaussian?

Plan:

1) Troubleshoot program on lab computer to fix memory issue

2) Fit cross section data for substances from Andrea (straight forward now that I’ve done this before)

3) If compounds, insert into code a function that adds the cross sections together. If separate elements, insert into code a function which picks if the neutron collides with one or the other, which is weighted towards larger nuclei

4) Add the distribution of mean free paths into code (very easy)

5) Find fraction that are absorbed before thermal on average. Put resonates data into finished code and this should work.

I installed my code along with the user manual to “tchita” (the one next to the mac).

I had an issue running the code that has never occurred on my machine. A memory error was called while putting a value into a list. I will proceed by starting the code with a very small neutron energy (1 ev) and see if the code works. If it does then the machine is the issue, in which case I would need find a more efficient way to store data. If it still does not work then there must be an issue in the code, but I doubt this.

Now when I changed the width of the resonance to .02% of the energy of the resonance and made a varying energy loss I found that only some neutrons get absorbed before thermal energies.

I have been reading up on how to find the mean free path for a compound. From what I can find it seems that I can just sum the cross sections of the individual elements to make a new cross section which is the effective cross section. This approximation causes issues when you consider other reactions, but if you only consider collisions then this should be accurate (which is what I do until the neutron is thermal).