Unable to see the presence of defects

Respected FLUKA experts,
I am performing simulations using FLUKA where I want to see/detect the presence of defects using a 65 keV of x-ray beam. Using the BXDRAW entry of the mgdraw when I plot the graphs I am not able to see the difference when there is void and without void. Is there something wrong I am doing?
without_void.flair (6.2 KB)
without_void.inp (4.9 KB)
with void.flair (6.3 KB)
with void.inp (5.0 KB)
mgdraw-1025.f (10.1 KB)
mysource_ng1.f (19.0 KB)
spectrum01.txt (18.7 KB)
here is the graph

there is also a second question regarding the same problem, that I also want to introduce some objects of different shapes (triangle, square, circle) and wanna to see that how different shapes affect the back scatter photons.
While looking at the literature I found a paper (doi: 10.2478/nuka-2023-0008) Study of a Compton backscattering wall defects detection device using the Monte Carlo method where they did a similar studies to detect the defects. But I want more variables then the mentioned in the paper and therefore decided to go with bxdraw. Besides this I am not sure that how they plotted the figure 2 and figure 7.
I will be very thankful for your guidance in advance.

Respected Riya,
Can you please help me with the following query?

Here is the ling for further literature may you have some idea that will be helpful for me

Literature 1# View of Desempenho de colimadores cônicos para um experimento de espalhamento Compton usando o método de Monte Carlo / Performance of conical collimators for a Compton scattering experiment using the Monte Carlo method

Literature 2# https://discovery.ucl.ac.uk/id/eprint/1560333/1/102120R.pdf

Literature 3# http://www.uel.br/grupos/gfna/backscattering.pdf

Dear @muneeb.wajid.r ,

I am not aware of this. I think the experts will reply to your query in your post.

Regards,

Riya

Dear Abdul,

it is unclear to me how you are processing the mgdraw results to get your plot.

I would suggest implementing a mockup detector surface similar to the ones in the linked literature instead of using the mgdraw routine to score the Compton backscattered X-rays.

Cheers,
David

Respected Horvath,
I am thankful for your reply. I tried to implement a mockup a detector like they did in the literature. But I have some confusion here. Like in the picture I have set up an air region where the detector can be setup at some angle and to score the photons being scattered back using the USRBDX from target to air region. Is this what you want to suggest?

Dear Abdul,

my idea was to create separate, small regions in the AIR, above/below the beam, and use them to score the particle fluence.

Cheers,
David