thermal scattering data

User Support
1

Hello. I know if I have a moderating material like water , I should assign thermal scattering data , such as water.add_s_alpha_beta(‘c_H_in_H2O’) .

MCNP is also used. When I encountered the thermal scattering data of poly.01t (Hydrogen in Polyethylene) in MCNP, how should I express it in Openmc? Thank you!

2

In this case, the correct identifier is c_H_in_CH2. Note that when you use the add_s_alpha_beta() method, it will automatically try to figure out the correct name even if you pass a name that is not in the correct format. It is also aware of most of the common MCNP cross section names, so if you do run add_s_alpha_beta(‘poly’), it knows that you are trying to specify H in polyethylene:

import openmc
m = openmc.Material()
m.add_s_alpha_beta(‘poly’)
/home/romano/openmc/openmc/material.py:593: UserWarning: OpenMC S(a,b) tables follow the GND naming convention. Table “poly” is being renamed as “c_H_in_CH2”.
warnings.warn(msg)

3

Thank you for the information!

Paul Romano <paul.k.romano@gmail.com> 於 2019年2月7日 週四 上午12:26寫道：