how to create at circular surface in a flunet case for post processing
 

Hi all....I want to display my intensity profile on a circular surface. my domain is a cube. I would like to display the intensity profile on a surface say z=0. But I donot need the whole surface. I need only a part of this surface. Z=0 iso surface is giving me a rectangular surface length and height equal to my domain length and height. but I need to display profile only on a half circular surface, which is starting at the center of Z=0 iso-surface and with diameter equal to the length of the domain.

I tried different things...but unable to succeed. please help me.

Hi All....looking forward to your suggestions to solve my problem. It will be great help to me, if somebody can give me a way how to do it.

Regards