Error when increasing $MXSTACK in array_sizes.h file in egs_chamber

[Fisicomelo]

Hello guys,

I am trying to run egs_chamber with a BEAM accel as shared library, and I am constantly getting this error:
Stack overflow in BREMS! np = ****** Increase $MXSTACK and try again
However, if I try to increase $MXSTACK from 9e6 to 1e7 in the array_sizes.h file in egs_chamber and try to recompile I get another error (please, see image) that does not allow me to compile it:

I have tried to increase $MXSTACK in /home/omega/EGSnrc/HEN_HOUSE/src/egsnrc.macros as well but I still have the same (first) error.

Does anyone have any suggestion?

DBS settings:
Splitting field radius: 10
SSD: 100
Beam splitting number: 800

[rtownson]

I haven't been able to reproduce this. Does your array_sizes.h file look like this?

#ifndef ARRAY_SIZES_
#define ARRAY_SIZES_

#define MXMED   40
#define MXSTACK 1000000

#endif

And egsnrc.macros:

PARAMETER $MXSTACK=1000000;    "STACK SIZE"

Have you made any other changes?

[Fisicomelo]

Hi Reid,
Yes, it is except for the value of $MXSTACK. In your case it is 1e6 and I am trying to increase up to 1e7 and that is when I can't compile anymore. I can compile egs_chamber only if I increase up to 9999999, but then when I try to run the code, I get the error massage again saying that I need to increase $MXSTACK.
I believe the version installed at te University cluster is from 2021. I will install my own version in home area and try again.
Thank you, Reid

[Fisicomelo]

Hi @rtownson ,

I tried to run a very small number of histories in egs_chamber (1e4) and without splitting in my accelerator (DBS = none) I still get the same error asking to increase $MXSTACK. I guess the problem is probably in the accelerator that I built, although I have already tried to re-build many times.
Let me know if you have any clue.

Thank you.

[rtownson]

Do you have any issues running the BEAMnrc accelerator on its own? Can you run the egs_chamber simulation with a different BEAMnrc accelerator? E.g. using BEAM_EX16MVp.

[Fisicomelo]

Hi Reid,
I forgot to mention. That is the weird thing. There is no issue when I run the accelerator (this Elekta one that I built) itself. It runs just fine. It also works to run egs_chamber with other accelerators such as the Co60 unit that I also built it. I guess next steps would be to run the same egs_chamber inputfile with the BEAM_EX16MVp as you suggested and also run a different egs_chamber inputfile (some of the examples) with the Elekta accel. Thank you for the suggestions. I will keep you upadted.

[Fisicomelo]

Hello @rtownson

I have performed some tests, and the source of problem was probably my egs_chamber input file that for some reason was corrupted. I created a new inputfile from another one that was fine and now it works. It is still weird why it flagged an error message to increase $MXSTACK, but at least everything is fine now.
Thank you so much for the support.

Cheers

[Fisicomelo]

Fantastic! Thank you, Reid. I really appreciate it.