Dear FLUKA users and experts! I want to define a cylindrical geometry in the direction of 45 degrees or 135 degrees. How should I define it. As shown in the figure. [image] I hope to receive the answers from all experts Cheers, Chailin

Dear @CHAILIN , You can achieve that using the ROT-DEFI instruction. Have a look at the advanced geometry lecture from the last Fluka course to understand how it works.