Hi all:
Is there any feasibility for me to indicate a temperature for a specific isotopic in materials.xml, and get this isotopic’s cross-section? (For example a key words “temperature”)
Hi,
If i may jump in… When we define a nuclide or element in materials.xml file, we can specify “default_xs” which will assign same cross section (temperature) to all the materials.
one way to over-ride this is to define a “xs” attribute with each one where this attribute will point towards the correct temperature cross section file.
<nuclide name="H-1" xs="02c" ao="2.0" />
<nuclide name="O-16" xs="02c" ao="1.0" />
<mateiral id="2"
<nuclide name="U-235" xs="03c" ao="1.0"/>
here material 1 is at 293K (stored in files with .02c) while uranium-235 is at 300K (stored in files with .03c).
Hope that helps.
Thank you Khurrum for your kindly help. It’s very nice of you.
I understand “xs” can provide cross-section based on the nuclear data.
My question is, for example I want to use U-235 cross-section data which temperature is 552K.
Does OpenMC have a interpolation for nuclear cross-section data, as a key word temperature=“XXX.XXXe-08” in materials.xml, which can obtain a isotopic cross-section based on user defined temperature?
O sorry I misunderstood your question. To the best of my knowledge there is no function in place for it in openmc yet. For such cases I am using linear interpolation i.e. Using appropriate weightage of 500 and 600 Kelvin libraries. Or you can always generate your own cross section at 552 Kelvin :). Hope this can help.
Khurrum is correct; there is currently no method to interpolate cross sections between two temperatures at which tabulated cross sections exist. We (i.e. MIT) are currently working on a methodology for evaluating cross sections at any temperature on-the-fly using a multipole representation. If you are interested in the details, please see the following journal article:
Thank you Dear Khurrum and Prof.Paul, I will work hard and learn more details from the journal article you provide me.
My question about fixed source problem confused me a lot and still not be replied, could you help me and give me some advise?