Dear experts,
I’m doing the radiation shielding simulation of a treatment room, and there are some problems in “Geometry”.
The concrete I built on the second floor(r2)is blank in “Geometry”. I want to know the reasons for this situation and how to solve this problem?
And “Errors found” is displayed in “Geometry”, but I didn’t find any errors in the geometric model after checking the input file. How should I solve them?
Your geometry is incomplete. You are missing the external black hole region enclosing your geometry to kill particles when the exit.
I presume you automatically generated your input by importing an mcnp file,
I would recommend to download the new flair v3 which has better conversion from mcnp, and if the problem persists there are additional automatic tools inside the new flair to help you correct the problem.
Dear expert,
I put the treatment room within the black hole according to your suggestion, but the spliced concrete area (r1) still shows errors. Is there something wrong with my geometry input?
Could you look at my input file again and tell me how to solve this problem?
Dear expert,
Thank you very much for your answer.
I revised it according to your suggestion, and my problem was solved. But I still have some doubts, why do I only need to modify r1, and do not need to modify R2 and R3 without affecting the geometric model?
And I found that my simulation can’t work normally in “RUN”. Can you help me find out why? 2021.5.10.flair (2.7 KB) 2021.5.10.inp (3.2 KB)
Your input needed a few small corrections and it runs normally.
Please find attached the modified project file with your input 2021.5.10.flair (4.6 KB)
I’ve added a GLOBAL card and some PHYSICS cards.
Also note that your input name contains “.” in the filename and the previous fluka versions cannot handle it.
“why do I only need to modify r1, and do not need to modify R2 and R3 without affecting the geometric model?”
The slides 4 and 12 give you the answer.
Basically, when you were trying to define your region r1 you had this:
r1: +b1 +b2 + … +b14
What does it mean? You can see it like being doing the intersection of these bodies in order to define the region r1. But, considering that these bodies do not have any space in common r1 is empty
Finally, in the second case:
r1: +b1 | +b2 | … | +b14
Here you are define 14 different zones, using the inside of each bodies, and finally with the operator ‘|’ you do the union of all these zones. Getting finally the desired region
Finally, let’s see why you do not need to do something similar in r2.
r2: +b16 -b1 -b2 - … - b18
Here you are extracting to b16 the bodies b1, b2, and so on. This is well defined and there is nothing to change there.