Recent content by quarkle

If you have a tiny or non-obvious geometry error (caused by rounding off errors, overlaps, skewed lattice etc) that you can't find with the MCNP plotter or Visual Editor, the following technique can help you pinpoint the error: - Change all cells to having a void material, but a non-zero...

I came upon this interesting article just today: https://www.quantamagazine.org/can-microbes-encourage-altruism-20170629/ The study in question: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241693/

Also, gamma rays from the U-232 and its daughters are energetic enough to damage electronics. A lot of extra shielding might be needed to protect the detonation circuitry. They also make it harder for people to steal U-233 material safely and without being easily detected.

I'm not entirely sure about the syntax, but MCNP5 does have the option to explicitly model a source with an angular distribution of particles emitted. Is that what you're looking for?

For this, you will need to use the tally multiplier functionality with the F4 tally. F4 gives a flux averaged over the volume of the cell in units of particles/cm**2 per source particle. Using a tally multiplier card, you can get MCNP to multiply this flux with the atom density of the target...

That happens when the cell description is too long. MCNP has a limit on that. Correcting this depends entirely on your problem geometry. If you can, break that cell into simpler Boolean expressions or different simpler cells.

This happens usually only if there is a geometry error. Perhaps the region where there is an error is so small, it might not be visible in the plot. If you carefully go through the output file, MCNP prints out details of every single lost particle, it's last known location, cell and transport...

I also think it might have to do with the way science is taught. From what I've seen (I may be wrong), most people I know passionate about science had particularly good teachers at some point or the other. I myself, disliked physics till college because my high school physics teacher was hostile...

Earlier I used to try and make atoms smash into each other to make hot glowing stuff to make electricity. The sun and other stars do that too! Other people might break atoms apart to make electricity. The leftover stuff isn't good for you if it's lying about open, so I make drums to pack it up...

I'm not really in the biology field, but I've always felt that 'fun', whether in humans or animals is what they do when are in a safe environment, are well-fed and, at that time, have no immediate concerns for survival (eating/running/sleeping). In more intelligent mammals, this fun (playing...

In that case its as straightforward as: F4:N (5<L1) (7<L2) Where L1 and L2 are the lattice numbers where cells 5 and 7 are located. If you want an average flux for all cells 5 and 7 all over the geometry it'll be: F4:N (5 7)

Do you want a separate tally bin for each cell or an average f4 tally for the same cell over all the lattice locations?

I'm not comparing the technical complexity, here (though that definitely plays a part), but the sheer diversity and number of people and countries involved in ITER is is much much larger. The logistics are a nightmare. Also, we need a whole lot of new physics development, techniques, tools...

I have worked in the Indian fusion community, and closely with people with ITER-India. From their perspective, the major reasons why ITER is proceeding so slow: People and politics. By politics I mean power struggles among people, not governmental politics. Each country and organizations has...

Perhaps you forgot to install the MCNP Data? It has a separate installation exe. If not, just reinstall the MCNP Data portion again, there might be a path setting error.