How to sample neutron spectrum?

Source Definition
1

Dear experts:
When I sample the neutron spectrum to simulate the neutron shielding problem.First I will show you my input spectrum:

image
image1563×1111 28.5 KB

Then I run the FLUKA code to test whether it is right of my input spectrum,but I get the strange spectrum:
image
image628×469 19.5 KB

From the simulated energy spectrum, it can be seen that high-energy neutrons can be correctly sampled, but low-energy neutrons cannot be sampled. I would like to ask if FLUKA can properly sample low-energy particles, or do I need to rewrite the sampling function in the source fortran file?

2

Dear Dejun,

It is definitely possible to correctly sample the neutron spectrum in FLUKA.

Please share your current input, spectrum, and source routine files, so we can have a look on what is going wrong in your case.

Cheers,
David

3

Dear Horvath,
Thank you for your reply.
This is the current input,spectrum and source routine files,please have a look on what is going wrong in my case.
neutron.txt (9.8 KB)
source_newgen.f (20.9 KB)
source_routine.flair (3.1 KB)
source_routine.inp (1.1 KB)

Cheers,
Dejun

4

Dear Dejun,

you need to uncomment the line:

energy_logical_flag = .true.

to set the particle energy, instead of momentum,

Cheers,
David

5

Dear David,
Yes, this problem has been solved. It was my oversight that led to commenting out this line. Thank you very much for your answer, and thank you again.

Cheers,
Dejun