USRBDX card results are empty


I am doing fluka simulations to optimize the thickness of x-ray target (tungsten). I have an electron beam of 9 MeV. I hit it on x-ray target. On the other side I want to have Photon flux and electron leakage. I wanted to score electron after target using USRBDX Card in detector region. But I get no flux(0) at output? What could be the problem?
Am I using the Usrbdx Card the wrong way?

Moreover, If I use usrbin card to score anything (like energy deposited or photon flux) in detector region by using region in type in what 1, then I also get the following error.

However, If i define a mesh then i get the results for usrbin.

I have attached my flair file here.

Target_optimization.flair (3.0 KB)
Target_optimization.inp (1.4 KB)

Dear @anum.asif,

USRBDX is a boundary crossing estimator, so you need two regions that are in contact. For example, if you choose Reg1: VOID and to Reg: Target for your USRBDX scoring, your output will not be empty anymore.

Regarding your second question related to USRBIN region scoring, you should first create a geometry plot and then plot your results.

All the best,

Thankyou @Mihaela_Parvu . It solved my question for usrbdx. And now I am getting results for usrbdx.

Can you explain me how to create a geometry plot first in usrbin for my error listed above?

You can plot the 1D projection in order to check the values.