I’m working on a senior capstone project and am trying to reduce my neutron leakage rate. Currently, I have adjusted my source and model to produce a leakage fraction of 0.25074 +/- 0.00006. This is down from nearly 0.87.
My model involves a shielded subassembly and involves air as a region outside of the components in my model but inside my void. The air is also defined as a cell, and I do not care about any of the data from the air. I am wondering if there is a way to kill all particles that enter this air, or weight them less. I have not found much documentation or examples on this for openMC. I am looking for a built-in feature comparable to MCNP’s “Importance” keyword. Any help/direction is greatly appreciated.
@wxinyan is correct. Here’s a potential solution. If you have a surface defined without a material assigned, OpenMC automatically considers this to be void. Thus, none of your specified tallies are collected in this region and all particles are killed. This has some impact on leakage in my case, roughly a 1% decrease. I am investigating the surface crossing weight window and will let you know what I find!
Hi uc_mstl_1
What I am doing is about deep penetration detection, but I found that the count in my counting area is 0. Like you, I also want to know if openmc has an IMP function similar to MCNP, so that I can increase the particles in the counting area. quantity. But after reading the user manual, I found that there is no such thing, so now I am learning the weightwindow function. I don’t quite understand some of the parameters in it. If possible, we can communicate together.
weightwindow is the IMP equivalent in OpenMC. Here is an example below;
First, set up a mesh where you want to apply weights. The biggest differences between OpenMC weightwindow and MCNP IMP is that weightwindow is mesh-based, while IMP is cell based.
