Source definition for each primary

Advanced Features and User Routines
1

Dear all,

I have a question regarding particle generation using source_newgen.f user routine.
I am trying to generate particles on a straight line in a cylindrical region.
As an example, if I want my particles to be generated on a straight line on a plane at z=50 cm and at angle theta=55 degrees, my code looks like this:

  !random = FLRNDM(xdummy)
  !angle = 360 * random
  !theta = angle * PIPIPI/180
  R = sample_flat_distribution (-28.5D0 , 28.5D0 )
  theta = 55 * PIPIPI/180 !example for 55 degrees
  coordinate_x = R * cos(theta)
  coordinate_y = R * sin(theta)
  coordinate_z = 50D0

My question is the following: Is it possible to generate 1000 particles on a straight line at a specific angle for each primary event, and then for the second primary event, generate the particles on a straight line at a different angle? If not, is it possible to generate 1000 primaries on a line and then distribute the next 1000 on another line, and so on?

Thank you in advance for your assistance,
Mihaela

3

Dear Mihaela,

in case you don’t want to use event-by-event scoring, you can save the parameters of the line and get new values only after every 1000 primaries using a counter variable.
See: SAVE (FORTRAN 77 Language Reference)

Cheers,
David

1 Like
4

Dear David,

Thank you so much! I managed to generate my particles accordingly.
One more question. Is it possible to generate the particles along the line in one specific region (for example along the yellow line)? I noticed that regionsource subroutine overwrites the previously defined variables.

image
image779Ă—644 3.79 KB

All the best,
Mihaela

5

Dear Mihaela,

you just need to modify the regionsource subroutine so that the line sampling is done there.

Cheers,
David

1 Like
6

Dear David,

Thank you very much for your help! I managed to do it!

Best,
Mihaela